Chapter 3. Infectious Diseases | Atlas of Pediatric Emergency Medicine, 2e | AccessPediatrics

Exudative tonsillopharyngitis in an adolescent presenting with high fever, sore throat, and tender anterior cervical adenopathy and a throat culture positive for GABHS. Intensity of exudates can be absent in mild cases to formation of a membrane covering the entire pharynx in severe cases. (Photo contributor: Mark Silverberg, MD.)

Scarlet fever rash may appear 12 to 24 hours after the onset of fever. The patient’s forehead and cheeks are flushed with circumoral pallor and a rash of tiny papules that appears like a “sunburn with goose pimples,” has the texture of sandpaper, and blanches prominently with pressure. The rash begins in the axilla, groin, and neck and generalizes, sparing the palms, soles, and face within 24 hours. Other findings include strawberry tongue, exudative tonsillopharyngitis, and Pastia sign (an accentuation of the rash in skin folds with fine line of petechiae). Desquamation may occur after 7 to 10 days and usually continues for 2 to 3 weeks, but can last up to 2 months. When desquamation occurs, it begins as fine flakes on the face, then precedes over the trunk, hands, and feet. The extent and duration of desquamation are directly related to the intensity of the rash. Scarlet fever rash is caused by one or more of several erythrogenic exotoxins produced by GABHS strains and occurs in children who lack the immunity to the exotoxin. The portal of entry is oropharynx in the majority and rarely a surgical wound (surgical scarlet fever). Most cases occur in children between 2 and 8 years of age in winter and early spring.

Figure 3.2 ▪ Acute Suppurative Cervical Lymphadenitis.

Both throat culture and lymph node aspirate culture were positive for GABHS in this girl presenting with anterior cervical lymphadenitis. (Photo contributor: Binita R. Shah, MD.)

Both streptococcal pharyngitis and scarlet fever are self-limited diseases. Fever abates within 3 to 5 days (in absence of suppurative complications) with resolution of all signs and symptoms within 1 week. Tonsillar hypertrophy and lymph nodes take several weeks to return to their usual size. Suppurative complications include acute cervical lymphadenitis, peritonsillar cellulitis or peritonsillar abscess, retropharyngeal abscess, acute otitis media, acute sinusitis, mastoiditis, pneumonia, toxic shock syndrome (TSS), intracranial complications (eg, meningitis, brain abscess), bacteremic spread with metastatic infection (eg, septic arthritis, osteomyelitis), and nonsuppurative complications include acute rheumatic fever (ARF) and acute glomerulonephritis. Differential diagnosis of exudative tonsillopharyngitis includes viral infections (eg, adenovirus, Epstein-Barr virus, herpes simplex virus [shallow tonsillar ulcers with gray exudates), other bacteria (diphtheria, tularemia), and Candida (immunosuppressed patients). Differential diagnosis of scarlet fever includes Kawasaki disease, staphylococcal scarlatina, staphylococcal scalded skin syndrome, viral exanthems, mycoplasma infection, TSS, drug hypersensitivity reactions, severe sunburn, and Arcanobacterium haemolyticum infection (tonsillopharyngitis with scarlatiniform rash; seen in adolescents and young adults).

Figure 3.3 ▪ Scarlet Fever.

(A) Erythematous scarlatiniform rash with sore throat and fever were seen in this child. Note the prominence of the rash in the neck, axillas, and groin (all pressure sites). (B) In dark-skinned patients, the scarlet fever rash may be palpated more easily as “sandpaper texture” than seen. Note the accentuation of the rash in the neck area and absence of conjunctival injection and red lips (characteristic features of Kawasaki disease that also presents with scarlatiniform rash). (Photo contributors: Bipin Patel MD [A] and Binita R. Shah, MD [B].)

Emergency Department Treatment and Disposition

Confirm diagnosis by either performing a throat culture (vigorously swab tonsils and posterior pharynx to obtain an adequate sample) or rapid antigen detection test as accurate clinical differentiation of viral and GABHS pharyngitis is not possible. A positive rapid antigen test is diagnostic; a negative test requires a throat culture. Consider starting therapy after a positive rapid antigen detection test; withholding therapy for 24 to 48 hours while awaiting throat culture results does not increase the risk of ARF. Prescribe antibiotics (before throat culture result) for patients with any of the following: prior history of ARF, scarlet fever, suppurative complications (eg, peritonsillar cellulitis or abscess), or patients unavailable for follow-up. Prescribe penicillin V (drug of choice) orally for 10 days (emphasize the importance of completing the full 10-day course regardless of clinical improvement to prevent ARF). If compliance is an issue, alternatives include amoxicillin (single daily dose for 10 days) or benzathine penicillin G (BPG) or mixtures of BPG with procaine penicillin (to reduce pain) given intramuscularly as a single dose. For patients allergic to penicillin, clarithromycin, azithromycin, or clindamycin are alternatives. Children can return to school after 24 hours of antibiotic therapy. Routine posttreatment follow-up culture is not needed.

Figure 3.4 ▪ “Strawberry Tongue” of Scarlet Fever.

(A) White strawberry tongue (edematous red papillae projecting through white-coated tongue is seen on the second day of illness in a child with scarlet fever). (B) The real “red strawberry tongue”? (C) Red strawberry tongue (as white coating disappears, red tongue is seen studded with prominent papillae that stand out). Other differential of strawberry tongue includes Kawasaki disease and toxic shock syndrome (TSS; Staphylococcus aureus–mediated TSS and Streptococcal-mediated TSS). (Photo contributor: Binita R. Shah, MD.)

Figure 3.5 ▪ Desquamation of the Hand and Foot in Scarlet Fever.

(A) and (B) Photographs taken on the eighth day of illness in a child with scarlet fever. (Photo contributor: Binita R. Shah, MD.)

Figure 3.6 ▪ Desquamation as Presenting Sign of Scarlet Fever.

This child was brought to emergency department because of this prominent (and frightening to parents) desquamation seen in both hands and lower extremities. He had a sore throat and low-grade fever with “goose bumps” 9 days before this finding. Desquamation may be a presenting sign of scarlet fever (if the initial acute phase is mild and overlooked). Large sheaths of epidermis may be shed from the palms and soles in a glove-like pattern, exposing new and tender epidermis beneath. (Photo contributor: Binita R. Shah, MD.)

Pearls

Most common clinical illness produced by GABHS is acute tonsillopharyngitis.
Coryza, cough, conjunctivitis, hoarseness, diarrhea, discrete ulcers, or stomatitis in a child with pharyngitis strongly suggests a viral etiology and not GABHS infection.
Exudative pharyngitis in children <3 years of age is rarely of streptococcal etiology and diagnostic studies for GABHS are not recommended routinely.
Scarlet fever occurs most commonly in association with pharyngitis and rarely with pyoderma or an infected wound. Tonsillopharyngitis is absent in surgical scarlet fever.
Skin tenderness is absent in scarlet fever, as opposed to the prominent skin tenderness of staphylococcal scarletina.

Impetigo

Clinical Summary

Impetigo is a contagious superficial skin infection occurring in two forms: bullous and nonbullous (accounts for >70% of cases). Bullous impetigo is caused by Staphylococcus aureus, whereas the nonbullous form is caused by either group A β-hemolytic streptococcus (GABHS or S pyogenes), S aureus or both. Nonbullous impetigo is most commonly seen in preschoolers and begins as small vesicles progressing to pustules that extend radially with satellite lesions. Vesiculopustular lesions rupture, exposing a red, moist base and purulent discharge, which forms thick, yellow, or honey-colored adherent crusts. Lesions are usually painless, asymptomatic and have little surrounding erythema, and tend to occur on traumatized skin (eg, insect bite, abrasion), commonly in hot, muggy summer months. Exposed body surfaces such as the face, nose, mouth, or extremities are most commonly affected. Pruritus is common and scratching causes lesions to spread through autoinoculation. Regional lymphadenopathy is common, but constitutional symptoms are absent or minimal.

Figure 3.7 ▪ Non Bullous Impetigo.

(A) Exposed body surfaces such as the face (around the nose and mouth) are the most common sites. (B) Lesion with a honey-colored crust on the upper extremity. Removal of the crust reveals bright red, shiny erosions. (Photo contributor: Binita R. Shah, MD.)

Bullous impetigo is most commonly seen in newborns, infants, and preschoolers. The bacterial reservoir is the upper respiratory tract (eg, nose, conjunctiva) of asymptomatic carriers who spread the pathogen to the child’s skin. Lesions result from exfoliative toxin produced by bacteria at the contact site and begin as vesicles that progress to flaccid bullae with little or no surrounding erythema and clear to cloudy contents. Rupture leaves a narrow rim of scale at the edge of shallow, moist, red erosions (scalded skin appearance). Nikolsky sign is absent (unlike staphylococcal scalded skin syndrome). Lesions may be few and localized (usually covered areas) or numerous and widely scattered. Common sites are trunk, perineum, buttocks, and extremities. Lesions heal without scarring. There is no seasonal predilection.

Complications include acute poststreptococcal glomerulonephritis (impetigo by GABHS) and rarely serious secondary infections (eg, osteomyelitis, septic arthritis). Differential diagnosis of nonbullous impetigo includes ecthyma, herpes simplex virus infection, varicella, tinea corporis, and localized acute pustular psoriasis. In contrast, differential diagnosis of bullous impetigo includes bullous arthropod bites, poison ivy, child abuse (abusive burn injury), autoimmune blistering disease (eg, linear IgA dermatosis, pemphigus), and epidermolysis bullosa.

Figure 3.8 ▪ Bullous Impetigo.

(A) An intact bullous lesion filled with pus is seen in a 10-day-old neonate. He also had several round, ruptured erosions with a moist, red surface that were surrounded by a narrow ring of scale. Intact or ruptured bullae are round or oval in shape. (Photo contributor: Binita R. Shah, MD.) (B) An infant with numerous flaccid bullae filled with pus. (Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 93.)

Emergency Department Treatment and Disposition

Diagnosis is clinical, though the aspirate from the lesion may be cultured and Gram stain smear obtained. Though usually self-limited, untreated infection may last for weeks or months. Advise patients and caregivers to wash the affected area with antibacterial soap once or twice a day, and remove crusts, which can be softened by soaking area with a wet cloth compress, before applying topical therapy. Prescribe topical mupirocin ointment for localized impetigo (bullous or nonbullous) to eradicate the infection and prevent person-to-person spread. For generalized impetigo, or if there is involvement of multiple family members, prescribe systemic antibiotics covering mixed pathogens (GABHS and S aureus). Depending on the prevalence of methicillin-resistant or methicillin-sensitive S aureus in the community, consider oral penicillinase-resistant β-lactam drugs (eg, dicloxacillin), a first- or second-generation cephalosporin, clindamycin or doxycycline (children >8 years of age), or trimethoprim-sulfamethoxazole (for bullous impetigo). Refer patients with recurrence for evaluation and treatment of nasal carriage of S aureus.

Figure 3.9 ▪ Bullous Impetigo.

A 7-month-old infant was referred to the emergency department with this lesion that was thought to be an inflicted burn injury (child abuse). Aspiration of the lesion showed gram-positive cocci in clusters on Gram stain and culture was positive for Staphylococcus aureus. Posttraumatic paronychia due to S aureus should also be considered in the differential diagnosis. (Photo contributor: Binita R. Shah, MD.)

Pearls

A pathognomonic finding of bullous impetigo is a ring of scale at the periphery of an eroded lesion with a varnished surface.
Impetigo is a highly contagious infection and spread is facilitated by poor hygiene.
Staphylococci can be isolated from bullous impetigo lesions even though culture of staphylococcal scalded skin syndrome lesions is negative.

Figure 3.10 ▪ Bullous Arthropod Bites; Differential Diagnosis of Bullous Impetigo.

Close-up of bullous lesions on upper extremity (exposed area) due to arthropod bites. These lesions can be mistaken for either second-degree burns or bullous impetigo. (Photo contributor: Binita R. Shah, MD.)

Ecthyma

Clinical Summary

Ecthyma is a skin infection caused by group A β-hemolytic streptococci (GABHS or S pyogenes) and/or S aureus. Unlike impetigo, which is superficial, ecthyma involves deeper layers of the skin (the entire thickness of the epidermis to the upper reaches of the dermis). Ecthyma is seen in children of all ages and more frequently during summer. Predisposing factors include preceding minor skin trauma (eg, abrasions, insect bites), conditions associated with pruritus (eg, scabies, pediculosis), poor hygiene, and malnutrition. Lesions begin as vesicles or vesiculopustules with an erythematous base and rupture to form crusts and erode through the epidermis into the dermis, forming indolent “punched-out” ulcers with elevated margins. Ulcers become elevated and obscured by thick, dark greenish-yellow tightly adherent crusts that contribute to the persistence of the infection. Lesions are discrete and round and the most common site is lower legs. Lesions spread by autoinoculation and heal with scarring (unlike impetigo). Complications include cellulitis (untreated ecthyma) and poststreptococcal glomerulonephritis. Differential diagnosis includes cigarette burns (due to child abuse) and ecthyma gangrenosum (Pseudomonas aeruginosa infection).

Figure 3.11 ▪ Ecthyma.

An enlarging, slightly painful lesion which started as a “blister” on the forearm (without any prior history of trauma). Culture grew S pyogenes. Ecthyma is a discrete, round lesion with a dark crust in the center surrounded by a rim of shallow ulceration. (Photo contributor: Andrea Marmor, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical. Culture of the exudate (beneath an unroofed crust) reveals GABHS and S aureus. Advise washing the affected area with antibacterial soap and removal of the crust (facilitated by softening the crust by soaking with a wet cloth compress). Prescribe topical mupirocin therapy until all lesions have cleared. Depending on the prevalence of methicillin-resistant or methicillin-sensitive S aureus in the community, antibiotic options include oral penicillinase-resistant β-lactam drugs (eg, dicloxacillin) or a first- or second-generation cephalosporin, clindamycin or doxycycline (children >8 years of age).

Pearls

Thick crusts and underlying ulcers differentiate ecthyma from non bullous impetigo.
Ecthyma can be mistakenly attributed to cigarette burns of child abuse.

Figure 3.12 ▪ Ecthyma.

Multiple ecthyma lesions on the neck. (Photo contributor: Binita R. Shah, MD.)

Figure 3.13 ▪ Ecthyma versus Cigarette Burn.

Ecthyma (A) may be confused with cigarette burns (B). Ecthyma lesions are frequently of different sizes and are associated with crusting. Cigarette burns are circular punched-out lesions of uniform size with an average diameter of about 8 to 10 mm and have a smooth well defined edge. (Photo contributor: Binita R. Shah, MD [A]; Photo B. Reproduced with permission from: American Academy of Pediatrics: The Visual Diagnosis of Child Physical Diagnosis. The C. Henry Kempe National Center on Child Abuse and Neglect. Elk Grove Village, IL, American Academy of Pediatrics, 1994, p. 25.)

Erysipelas

Clinical Summary

Erysipelas is a distinct skin infection involving the uppermost layers of the subcutaneous tissue and cutaneous lymphatic vessels. It is caused by group A β-hemolytic streptococci (GABHS) in the majority and rarely by groups G, C, and B streptococci and occurs most frequently in infants, young children, older adults, and debilitated patients. The organism gains access to the deeper layers of the skin through breaks (eg, abrasions, lacerations, wounds, chronic ulcers). Predisposing factors include lymphedema, local lymphatic dysfunction, venous stasis, diabetes mellitus, malnutrition, and immunocompromised states. Onset is usually abrupt with constitutional symptoms (eg, fever, chills, malaise). Common sites are extremities (usually associated with a wound) and face (usually associated with pharyngitis). Initiating lesion is frequently inconspicuous and spreads peripherally with a raised, advancing border. The lesion is fiery red or salmon colored, hot, tender, tense, and indurated well-circumscribed plaque (sometimes with peau d’orange appearance) with a sharp demarcated border distinguishing it from the surrounding normal tissue. Reddish lymphatic streaks projecting from the margins of the lesion toward regional nodes may be noted. Intense edema may lead to formation of vesicles or tense bullae that later rupture and crust (bullous erysipelas). A “butterfly” appearance with involvement of both cheeks and nasal bridge may occur with involvement of the face. Regional lymphadenopathy may be present. Desquamation of involved skin may occur 5 to 10 days into the illness. Complications are same as with any GABHS infection. Erysipelas produces lymphatic obstruction leading to impaired lymphatic drainage causing lymphedema, which predisposes to recurrent episodes of erysipelas frequently at the same site and permanent local swelling. Differential diagnosis includes cellulitis, erysipelas-like presentation due to other bacterial infection (eg, S pneumoniae, S aureus), necrotizing fasciitis, and contact dermatitis.

Figure 3.14 ▪ Erysipelas.

A rapidly spreading tender facial rash and high fever were complaints of this girl. She had scratch marks on her cheek (portal of entry). The sharp demarcation between the salmon-red erythema and the normal surrounding skin is evident. Marking the margins of the erythema with ink (as seen in the photo) helps in following the clinical course (progression or regression) of the infection. (Photo contributor: Binita R. Shah, MD.)

Figure 3.15 ▪ Butterfly Rash of Erysipelas.

A rapidly spreading (<12-hour duration), tender, erythematous, indurated facial rash was seen in this girl with very high fever and leukocytosis. The sharp demarcation between erythema and the normal surrounding skin is evident. Erysipelas may create a “butterfly” appearance (mimicking the rash of systemic lupus erythematosus) on the face. She gave a history of falling off the monkey bar 2 days prior to appearance of this rash. Within 6 months after this infection, she presented again with a second episode of erysipelas at the same site. (Reproduced with permission from: Shah BR, Santucci K, Tunnessen W: Erysipelas. Arch Pediatr Adolesc Med 1995;149:55.)

Figure 3.16 ▪ Erysipelas.

Erythematous rash with classic honey-colored crust is seen in this facial erysipelas caused by GABHS. (Photo contributor: Rajni P. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical. Hospitalize patients with infection involving the face with systemic signs for intravenous antibiotics (eg, ceftriaxone) for at least 48 to 72 hours. Consider complete blood count (leukocytosis with a left shift), a blood culture, and/or a culture by aspiration from the advancing margin of the lesion. If cellulitis due to S aureus cannot be excluded by examination, depending on the prevalence of methicillin-resistant or methicillin-sensitive S aureus in the community, antibiotic options include penicillinase-resistant β-lactam drugs (eg, oxacillin) or clindamycin. Prescribe oral antibiotics for patients with milder presentations with a close follow-up. Advise rest, immobilization, elevation of the affected part, and cool, wet dressings as supportive therapy. Extension into deeper soft tissues is rare and surgical débridement is not necessary.

Figure 3.17 ▪ Cellulitis; Differential Diagnosis of Erysipelas.

Cellulitis spreads more slowly and extends more deeply into the subcutaneous tissues; hence, the borders of cellulitis are ill-defined (in contrast to erysipelas). Group A β-hemolytic Streptococcus and Staphylococcus aureus are common pathogens causing cellulitis. Streptococcus pneumoniae and Haemophilus influenzae can cause buccal cellulites associated with bacteremia in unimmunized young children. (Photo contributor: Binita R. Shah, MD.)

Pearl

Erysipelas is commonly referred as St Anthony’s fire because it spreads rapidly like a fire, affecting a very large area of the skin within a short period of time.

Necrotizing Fasciitis

Clinical Summary

Necrotizing fasciitis (NF; also known as streptococcal gangrene, flesh-eating bacteria syndrome, hospital gangrene, or necrotizing erysipelas or necrotizing cellulites) is a life-threatening bacterial infection of the fascia and subcutaneous tissues. Patients present with an erythematous, indurated, tender, ill-defined plaque (often mistaken for cellulitis) that manifests disproportionate pain and tenderness. The lesion is dusky purple with vesicles/bullae sometimes filled with maroon or violaceous fluid. Subcutaneous emphysema or crepitus (some cases) may be present and there may be loss of feeling on the skin. The lesion expands rapidly with undermining of overlying skin (important clue for diagnosis), progressing to necrosis and gangrene. Signs of toxicity include (high fever, malaise, altered sensorium, shock). Fournier’s gangrene is NF of perineum, scrotum, and penis. Predisposing factors include infections (eg, varicella), contaminated surgical wounds, IV drug or alcohol abuse, and immunocompromised states. Bacterial myonecrosis refers to involvement of the muscle. Various etiologies include S pyogenes (most common pathogen), groups B, C, or G streptococci, S aureus, P aeruginosa, anaerobes (eg, Bacteroides, Peptostreptococcus, Clostridium spp) and polymicrobial (gram-negative bacilli [eg, Escherichia coli, Proteus spp] and anaerobic bacteria). The majority of cases occur as extensions from localized nearby skin infections that expand along fascial planes, leading to edema, vascular injury, and thrombosis resulting in widespread necrosis of the superficial fascia, adjoining tissues, and deeper layer of dermis. Associated compression or destruction of nerves innervating skin results in anesthesia. Differential diagnosis includes erysipelas, cellulitis, and purpura fulminans. Complications include multiorgan failure with oliguria, acute respiratory distress syndrome, disseminated intravascular coagulation, myocardial failure, and fluid and electrolyte disturbances (extravasation of intravascular fluid into tissues).

Figure 3.18 ▪ Necrotizing Fasciitis.

(A) A 9-day-old neonate presented with high fever, moaning, and slightly indurated swelling with bluish discoloration on the back. (B) Within 12 hours, there was vesiculation and purplish discoloration. This photograph was taken 8 hours following the first surgical exploration and débridement and shows the underlying muscle and necrotic borders. (C) Close-up showing necrotic borders and pus over the underlying muscle. Both blood and tissue cultures grew Staphylococcus aureus. (D) Multiple surgical explorations and débridement were performed followed by skin grafting during recovery. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Necrotizing fasciitis is a medical emergency. Consult surgery emergently for surgical exploration, biopsy (frozen-section biopsy allows rapid evaluation of the pathology to confirm the diagnosis and identification of pathogens underlying the intact skin), débridement of all necrotic tissue, and fasciotomy. Consult infectious disease specialist and begin empiric broad-spectrum IV antibiotics (eg, ampicillin-sulbactam or ampicillin with either clindamycin or metronidazole and vancomycin). Obtain CBC, comprehensive metabolic panel, and coagulation profile (leukocytosis with immature cells, anemia, hyponatremia, hypocalcemia, hypoproteinemia, evidence of disseminated intravascular coagulation, and elevated values of blood urea nitrogen, creatinine, and liver enzymes may be noted). Perform fine-needle aspiration from the involved area (may show presence of pus and bacteria on Gram stain), and send aspirated material and blood culture for both aerobic and anaerobic pathogens. Consider radiograph of the affected area (may show presence of subcutaneous gas, which mandates rapid surgical exploration; however, absence of soft tissue gas does not exclude diagnosis). Consider computed tomographic scan, ultrasound, or magnetic resonance imaging for diagnosis in patients with early signs (when diagnosis is unclear); however, these modalities should never delay immediate surgical exploration in patients with obvious signs. Hospitalize all suspected cases of NF to ICU for ongoing management. Repeat débridement within 24 to 48 hours may be necessary because of continued spread of the infection into surrounding tissues. Other treatment modalities may include hyperbaric oxygen.

Figure 3.19 ▪ Necrotizing Fasciitis; Fournier’s Gangrene.

(A, B) Coronal and axial CT images demonstrate air within the soft tissues of the left perineal region (arrows) compatible with necrotizing fasciitis. (Photo/legend contributors: Nikita Joshi, MD/John Amodio, MD.)

Pearls

Sine qua non of NF is fascial necrosis with widespread undermining of the skin. The ability to pass a sterile instrument along a plane superficial to the deep fascia without resistance is indicative of NF.
Presence of an indurated “wooden” plaque adjacent to infected skin coupled with extreme pain in an area of rapidly advancing edema and inflammation are important clues.
Marked systemic toxicity and pain out of proportion to the local findings (in contrast to the usual patient with cellulitis) suggest NF.

Ecthyma Gangrenosum

Clinical Summary

Ecthyma gangrenosum is a pathognomonic cutaneous manifestation of Pseudomonas aeruginosa septicemia; other skin lesions include subcutaneous nodules, vesicular lesions, gangrenous cellulitis, and petechiae rash. Ecthyma gangrenosum usually occurs as a result of bloodborne metastatic seeding to the skin from the bacteremia, or rarely as a primary lesion without bacteremia. Predisposing factors for Pseudomonas septicemia include immunosuppression (eg, malignancy, diabetes, malnutrition, cystic fibrosis), debilitated preterm newborns, severe thermal burns, disorders leading to severe neutropenia or pancytopenia, hospitalized patients on intensive antibiotic treatment, or those with indwelling urinary, arterial, or venous catheters. Skin lesions begin as hemorrhagic (purpuric) macular, vesicular, pustular, or bullous lesions and evolve into punched-out necrotic ulcers with raised edges with a rim of erythema. Lesions remain localized or more typically extend over several centimeters ultimately becoming a round, indurated, painless lesion with a characteristic central grey-black eschar. Either a single ulcer or multiple (noncontiguous) ulcers may be seen. Common sites include perineal or gluteal region, extremities, trunk, face, intertriginous areas, and axilla. Lesions take a few weeks to heal. Differential diagnosis includes ecthyma gangrenosum–like lesions in sepsis from other pathogens (eg, Candida spp, S aureus, S pyogenes), thermal burns, pyoderma gangrenosum, purpura fulminans, and brown recluse spider bite.

Figure 3.20 ▪ Ecthyma Gangrenosum.

(A) Purpuric macular lesions involving the perineum, buttocks, and trunk in a malnourished infant (fed only diluted soy formula) presenting in septic shock. (B), (C), and (D) Close-up of lesions showing progression to necrotic ulcers with dense black eschars in the center. Note the surrounding erythematous halo with raised edges. Both blood and wound cultures were positive for Pseudomonas aeruginosa. (A, B, C. Reproduced with permission from: Secord A, Milla C, Shah BR: Picture of the month. Ecthyma gangrenosum. Am J Dis Child 1993;147:795; and Photo D. Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 99.)

Emergency Department Treatment and Disposition

Stabilize patient based on abnormal vital signs (patients with ecthyma gangrenosum are usually septic). Hospitalize to ICU for IV antibiotic therapy and general supportive care including wound care. Begin antibiotic therapy with an aminoglycoside (eg, tobramycin, gentamicin) and an antipseudomonal penicillin (eg, ticarcillin, piperacillin). Obtain CBC (usually neutropenia especially with septicemia), comprehensive metabolic panel, coagulation profile, blood culture and needle aspiration and culture of the lession (Gram’s stain may show presence of bacteria). Consult dermatologist if diagnosis is unclear; a skin biopsy may show numerous bacteria invading the blood vessels (invasion of media and adventitia of vein walls deep in the dermis with very few inflammatory cells).

Pearl

The characteristic findings of ecthyma gangrenosum are punched-out ulcers with a black eschar, surrounded by a rim of erythema.

Toxic Shock Syndrome

Clinical Summary

Toxic shock syndrome (TSS) is a potentially fatal systemic infection by toxin-producing strains of either S aureus (S aureus–mediated TSS) or S pyogenes (S pyogenes–mediated TSS). Diagnosis is made using published criteria. S pyogenes–mediated TSS occurs commonly in young children. Predisposing factors include varicella, HIV infection, diabetes mellitus, IV drug use, and invasive infections (eg, bacteremia, pneumonia, osteomyelitis, endocarditis).

Figure 3.21 ▪ Streptococcal Toxic Shock Syndrome.

(A) An 8-year-old girl presented with fever, hypotension, oliguria, and infected varicella lesions with multiorgan involvement. Note also the bilateral periorbital edema. Her blood culture was positive for S pyogenes. (B) Close-up of her nose showing honey-colored crusted lesions that are characteristic of S pyogenes impetigo. (Photo contributor: Binita R. Shah, MD.)

S aureus–mediated TSS is seen less commonly in children and most cases occur in women of age 15 to 34 years (reflecting association with menses). Nonmenstrual cases occur in people of all ages and in both sexes. Predisposing factors include use of tampons during menstruation, foreign body placements (eg, contraceptive sponge, central lines), primary S aureus infections (eg, cellulitis, endocarditis), postoperative wound infections, skin or mucous membrane disruptions (eg, burns, insect bites) and vaginal or pharyngeal colonization. Onset may be abrupt or preceded by a prodromal illness of fever, chills, and myalgias. Rash (seen almost always in first 24 hours of illness) may be faint and often mistaken for flush associated with fever. Beefy, red hyperemia of mucous membranes, conjunctival injection, strawberry tongue, erythema, and edema of palms and soles (findings similar to Kawasaki disease) are often seen. Pelvic exam is usually normal except for subtle erythema and edema of the skin of the inner thigh and perineum in menstrual TSS. The focus of the staphylococcal infection may be inconspicuous, with absent signs of inflammation in skin or wound lesions in nonmenstrual TSS.

Complications of TSS include acute renal failure, acute respiratory distress syndrome, overwhelming sepsis, DIC, and multiorgan failure leading to death. Differential diagnosis includes Kawasaki disease, scarlet fever, septic shock from other etiology (eg, meningococcemia, Rocky mountain spotted fever, gram-negative sepsis), measles or atypical measles, ehrlichiosis, leptospirosis, and drug hypersensitivity (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis).

Emergency Department Treatment and Disposition

Assess and stabilize vital signs, including fluid resuscitation and pressor agents, as indicated for septic shock. It may be impossible to distinguish clinically both forms of TSS; begin empiric antibiotic therapy that includes antistaphylococcal agents (eg, vancomycin and nafcillin) and a protein synthesis–inhibiting agent (eg, clindamycin). Obtain CBC, blood culture, cultures from the site of infection (skin or soft tissues), vaginal culture (for suspected menstrual TSS), serum electrolytes, BUN, creatinine, liver enzymes, and radiologic studies (as indicated). Consult surgery for exploration, biopsy, and resection of necrotic tissue in NF, drainage of the infected sites, or removal of foreign bodies. Hospitalize patients to ICU for further management.

Figure 3.22 ▪ Cellulitis in Streptococcal Toxic Shock Syndrome (TSS).

(A) Cellulitis involving the thigh and lower leg was seen in this child with AIDS. He presented with septic shock and multiorgan failure with a blood culture positive for S pyogenes. (B) Cellulitis of abdominal wall in an adolescent patient presenting with TSS. (Photo contributor: Binita R. Shah, MD.)

Pearls

Fever, rash, desquamation, hypotension, and multiorgan involvement are the hallmarks of TSS.
TSS can be confused with many other causes of fever with mucocutaneous manifestations.
Do not use clindamycin alone as an initial empiric therapy, as 1% to 2% of S pyogenes organisms in the United States are resistant to clindamycin.
Women with menses-related TSS may experience one or more recurrent episodes. Advise against use of tampons and barrier methods of contraception.

Figure 3.23 ▪ Desquamation in Streptococcal Toxic Shock Syndrome (TSS).

Shown here is desquamation that developed on the seventh day of the illness in an adolescent girl admitted with streptococcal TSS. (Photo contributor: Haamid Chamdawala, MD.)

Figure 3.24 ▪ Staphylococcal Toxic Shock Syndrome (TSS).

(A, B) Diffuse erythroderma with innumerable pustular lesions, high fever, vomiting, and diarrhea were the presenting complaints of this patient with TSS. Her blood culture was positive for S aureus. (C) Close-up showing pustular lesions. Culture of these pustules was negative for S aureus. (Photo contributor: Binita R. Shah, MD.)

Table 3.1 ▪ Streptococcal Toxic Shock Syndrome: Clinical Case Definition

Table 3.1 ▪ Streptococcal Toxic Shock Syndrome: Clinical Case Definition

Confirmed case

Presence of all laboratory and clinical findings below

Probable case

Positive culture from nonsterile site and all clinical findings below (and no other cause for illness identified)

Laboratory findings

Isolation of Streptococcus pyogenes

From a normally sterile site (eg, blood, cerebrospinal fluid, peritoneal fluid, tissue biopsy specimen)

From a nonsterile site (eg, throat, sputum, vagina, surgical wound, or superficial skin lesion)

Clinical findings

Hypotension

Systolic blood pressure ≤90 mm Hg in adults or <5th percentile for age in children

Multisystem involvement (at least two of following)

Renal

Creatinine ≥2 mg/dL for adults or two times or more the upper limit of normal for age

Coagulopathy

Platelets ≤100,000/mm3 or disseminated intravascular coagulation

Hepatic

Serum alanine and aspartate aminotransferases or total bilirubin values 2 times or more the upper limit of normal for age

Pulmonary

Acute respiratory distress syndrome

Skin

Erythematous macular rash that may desquamate

Soft tissue

Necrosis, including necrotizing fasciitis or myositis, or gangrene

Table 3.2 ▪ Staphylococcal Toxic Shock Syndrome: Clinical Case Definition

Table 3.2 ▪ Staphylococcal Toxic Shock Syndrome: Clinical Case Definition

Probable case

Meets laboratory criteria below and has 4–5 of the clinical findings listed below

Confirmed case

Meets laboratory criteria and all 5 clinical findings below, including desquamation, unless the patient dies before desquamation occurs.

Laboratory criteria

Negative results on following tests (if obtained)

Blood, throat, or cerebrospinal fluid cultures (blood culture may be positive for Staphylococcus aureus)

Serologic tests for Rocky Mountain spotted fever, leptospirosis, or measles

Clinical findings

Fever

38.9°C (102.0°F) or greater

Rash

Diffuse macular erythroderma (nonpruritic)

Desquamation

1 to 2 weeks after onset (particularly palms, soles, fingers, toes)

Hypotension

Systolic BP ≤90 mm Hg for adults

<5th percentile for age for children <16 years of age

Orthostatic drop in diastolic BP ≥15 mm Hg from lying to sitting

Orthostatic syncope or orthostatic dizziness

Multisystem involvement (three or more of the following)

Gastrointestinal

Vomiting or diarrhea at onset of illness

Muscular

Severe myalgia or creatinine phosphokinase >2 times the upper limit of normal

Mucous membrane

Vaginal, oropharyngeal, or conjunctival hyperemia

Renal

Blood urea nitrogen or serum creatinine level >2 times upper limit of normal or urinary sediment with ≥5 white blood cells per high-power field in absence of urinary tract infection

Hepatic

Total bilirubin, aspartate, or alanine aminotransferase level >2 times the upper limit of normal

Hematologic

Platelet count ≤100,000/mm3

Central nervous system–related

Disorientation or alterations in consciousness without focal neurologic signs when fever and hypotension are absent

Staphylococcal Scalded Skin Syndrome

Clinical Summary

Staphylococcal scalded skin syndrome (SSSS), also known as Ritter disease (SSSS of the newborn) and Lyell disease, is a toxin-mediated disease caused by Staphylococcus aureus that produces exfoliative toxins (ETA and ETB). S aureus colonizes mucous membranes of the nasopharynx, eyes, and other areas (eg, umbilical stump, circumcision site), producing a localized infection. Toxin produced in these areas circulates and acts specifically at the zona granulosa of the epidermis, leading to characteristic exfoliation. SSSS is most commonly seen in infants and young children (90% of cases <6 years; 62% <2 years of age). Infection in older children and adults is related to a decreased renal clearance of the toxin (eg, patients with renal insufficiency) or immunosuppression (eg, HIV infection).

Figure 3.25 ▪ Staphylococcal Scalded Skin Syndrome (SSSS).

(A) and (B) Radial sunburst crusting and fissuring around the orifices (mouth, eyes, nose) are hallmarks of SSSS (first day of rash in this patient). Note the absence of any mucous membrane involvement of the mouth or eyes (unlike prominent mucous membrane involvement of TEN/Stevens-Johnson syndrome). Within 24 hours after these photographs were taken, the skin over the trunk and perineum started wrinkling and flaccid bullae developed, followed by exfoliation in sheets revealing a red scalded-looking surface. (C) Large areas of exfoliation in a different patient with SSSS revealing a scalded-looking surface is shown. The borders of the exfoliating skin look like wet tissue paper. (Photo contributor: Binita R. Shah, MD, [A, B]; Photo C. Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 95.)

Patients present with a sudden onset of fever and irritability. Prominent crusting around the eyes and mouth occurs early. Pharyngitis, conjunctivitis, or superficial erosions of lips may be noted but intraoral mucosal surfaces are spared. The rash begins with an exquisite tenderness of the skin (eg, infant cries when held) as a diffuse erythematous scarlatiniform eruption (sandpaper texture, accentuation in perioral and flexural areas). Within 24 to 48 hours, the skin wrinkles and flaccid bullae develop, followed by exfoliation in sheets revealing a moist, red, shiny scalded-looking surface. Borders of exfoliating skin are rolled like wet tissue paper. Nikolsky sign is positive (slight rubbing of normal-looking adjacent skin results in blistering). Exfoliation can spread to entire body surface area with severe disease. Drying of exfoliated areas occur with flaky desquamation lasting 3 to 5 days and rash heals without scarring in 7 to 14 days. An associated staphylococcal infection such as impetigo or purulent conjunctivitis may be present.

Complications include fluid and electrolyte losses (loss of epidermal barrier) leading to hypovolemia, faulty temperature regulation, cutaneous infection (cellulitis), pneumonia, and septicemia. Differential diagnosis includes streptococcal scarlet fever, staphylococcal scarlatina or staphylococcal scarlet fever (some cases of SSSS do not progress beyond staphylococcal scarlatina [forme fruste of SSSS], bullous impetigo, drug eruptions (eg, Stevens-Johnson syndrome or toxic epidermal necrolysis [TEN]), toxic shock syndrome, epidermolysis bullosa, and pemphigus.

Figure 3.26 ▪ Staphylococcal Scalded Skin Syndrome.

(A) A 15-month-old infant presented with pustular lesions with cellulitis on the thumb, fever, and generalized scarlatiniform rash associated with skin tenderness. Subsequently he developed exfoliation in sheets, revealing a scalded-looking surface. Photograph taken on the third day after hospitalization (B) shows drying of exfoliated area with flaky desquamation. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Obtain cultures from the colonized sites like mucous membranes of nasopharynx, conjunctiva, or umbilical stump in neonates (typically blood culture and cultures of the skin and intact bullae are negative for staphylococci). Consult dermatology if diagnosis is unclear. A skin biopsy specimen (or a frozen section of an induced peel for a rapid diagnosis) will help to distinguish between SSSS and TEN. Admit all patients with widespread erosions and denuded skin for monitoring of fluid and electrolyte deficits and IV antibiotic therapy. Depending on the clinical situations and prevalence of methicillin-resistant and methicillin-sensitive S aureus (MRSA or MSSA) in the community, initial empiric antibiotic options vary, for example, vancomycin and nafcillin (life-threatening with septicemia) or clindamycin (without septicemia with substantial rates of MRSA and low prevalence of clindamycin resistance) or vancomycin (without septicemia with substantial rates of MRSA and substantial prevalence of clindamycin resistance). For penicillin-allergic patients, give vancomycin. Usual duration of therapy is 5 to 7 days; bacteremic or immunocompromised patients require a longer duration of therapy. Treat patients with localized SSSS with oral antibiotic therapy (eg, trimethoprim-sulfamethoxazole) with a close follow-up. Topical antibiotic is not required. Advice gently moistening and cleaning the skin with isotonic saline or Burow solution, applying an emollient to provide lubrication and avoiding wet dressings (may cause further drying and cracking).

Figure 3.27 ▪ Staphylococcal Scalded Skin Syndrome in a Neonate (Ritter Disease).

Following circumcision at birth, this 1-week-old neonate presented with extreme irritability, fever, numerous pus-filled intact bullae with some exfoliating lesions, and purulent conjunctivitis. Within 48 hours after these photos, generalized exfoliation over the entire body was seen. (Photo contributor: Binita R. Shah, MD.)

Figure 3.28 ▪ Staphylococcal Scalded Skin Syndrome.

(A, B) Superficial desquamation of the palm and dorsal foot is seen in a 2-month-old febrile infant (photos taken on second day of illness). Intact blisters followed by denuded plaques developed on the neck, abdomen, and back. Nikolski sign was positive. Eye and blood cultures were positive for S aureus. (Photo contributor: Katherine Siamas, MD.)

Pearls

Radial sunburst crusting and fissuring around the orifices (mouth, eyes, nose) are hallmarks of SSSS.
Nikolsky sign is a hallmark of SSSS, though this is also seen in Stevens-Johnson syndrome, TEN, and pemphigus vulgaris.
Early distinction between SSSS and TEN is extremely important. Therapy for SSSS includes antistaphylococcal antibiotics, whereas discontinuation of the offending drug, and aggressive supportive therapy in a burn unit may be lifesaving in TEN.

Table 3.3 ▪ Comparison of Staphylococcal Scalded Skin Syndrome (SSSS) and Toxic Epidermal Necrolysis (TEN)

Table 3.3 ▪ Comparison of Staphylococcal Scalded Skin Syndrome (SSSS) and Toxic Epidermal Necrolysis (TEN)

Age

Cause

Skin Tenderness

Skin Findings

Biopsy Finding Level of Split

Treatment

SSSS

Infants

S aureus

Always

Exfoliating skin white

No scarring

Granular layer within epidermis

Antibiotics

TEN

Older children

Drugs

Sometimes

Necrosis

Frequent scarring

Full-thickness epidermis

Discontinue drug; provide care in burn unit

Meningococcemia

Clinical Summary

Meningococcal infections are caused by Neisseria meningitidis. Invasive infection usually results in meningococcemia, meningitis or both. Strains belonging to groups A, B, C, Y, and W-135 account for most infections. Risk factors include inherited or acquired terminal complement deficiencies (C5 to C9), properdin deficiency, hypogammaglobulinemia, or asplenia (anatomic or functional). Children 2 years of age or younger (peak attack rate: infants <1 year) are most often affected, with another peak in adolescents (15 through 18 years of age). Incubation period is 1 to 10 days. Presenting signs and symptoms may be nonspecific mimicking a viral infection (eg, fever, chills, myalgias/weakness, headache), or septic shock, lethargy, coma, convulsion, signs of meningitis (nuchal rigidity, Kernig sign, and/or Brudzinski sign) or signs of multiorgan failure. Initially rash may begin as urticaria, macules or maculopapules, or petechiae that may coalesce to form larger ecchymotic areas with ischemic necrosis. Common sites for the rash are the trunk and extremities (may involve any area), mucous membranes (eg, palpebral conjunctivae), and clusters at pressure points. Differential diagnosis of purpura and petechial lesions includes septicemia with gram-negative or gram-positive organisms, enteroviral infections (eg, echovirus or coxsackie virus), Rocky Mountain spotted fever, Henoch-Schönlein purpura, petechiae from intractable coughing or vomiting, trauma (child abuse, accidental), factor deficiency (eg, hemophilia), measles/atypical measles, idiopathic thrombocytopenic purpura, thrombocytopenia from other etiology (eg, leukemia), drug reactions (eg, sulfonamides, penicillins), bacterial endocarditis, gonococcemia, epidemic typhus, Ehrlichia canis infection, and Stevens-Johnson syndrome.

Figure 3.29 ▪ Meningococcemia.

(A) Fever and petechial eruption (discrete pinpoint nonblanching lesions measuring 1 to 2 mm in diameter) associated with septic shock were the presenting signs in this child with meningococcemia. Use of a glass slide (as shown here) helps in determining if the rash is blanching or not. (B) An infant presenting with petechiae, septic shock and DIC with meningococcemia. (Photo contributor: Binita R. Shah, MD.)

Figure 3.30 ▪ Purpura Fulminans of Meningococcemia.

Purpuric lesions of <10 hours’ duration seen on the foot of an 18-month-old infant who presented with septic shock with DIC with meningococcemia. (Photo contributor: Binita R. Shah, MD.)

Complications include disseminated intravascular coagulation (DIC), purpura fulminans, cardiac (eg, myocarditis, congestive heart failure), pulmonary (eg, pneumonia, lung abscess), neurologic sequelae from meningitis (eg, subdural effusion or empyema, brain abscess) and Waterhouse-Friderichsen syndrome (bleeding into adrenals, shock, coma, and death). Poor prognostic factors include hypotension, hypothermia, leucopenia, thrombocytopenia, absence of meningitis, purpura fulminans, petechiae <12 hours before presentation, seizures, or shock on presentation.

Emergency Department Treatment and Disposition

Prompt recognition, stabilization, and immediate initiation of antibiotic therapy are essential in reducing morbidity and mortality. Stabilize vital signs, including fluid resuscitation and pressor agents, as indicated for septic shock. Begin IV antibiotic therapy with cefotaxime or ceftriaxone and vancomycin (meningococcemia and meningococcal meningitis are indistinguishable clinically from diseases caused by other bacterial pathogens, including S pneumoniae). Do not delay in initiating therapy for completion of diagnostic studies. Obtain CBC (leukocytosis or leukopenia, thrombocytopenia), coagulation profile (elevated prothrombin time, partial thromboplastin time, D-dimer, fibrin degradation products, and decreased plasma fibrinogen with DIC), serum electrolytes, BUN, creatinine, and liver enzymes (multiorgan failure), and urinalysis. Obtain cultures from blood and skin lesion scrapings. Gram stain of a petechial skin lesion may also be positive. Perform lumbar puncture (LP) only in a stable patient. With meningitis, cerebrospinal fluid (CSF) findings usually will show increased protein and decreased glucose levels, pleocytosis (predominance of polymorphonuclear leukocytes), and a positive culture. Hospitalize patient to ICU; droplet precautions in addition to standard precautions are recommended until 24 hours after initiation of therapy.

Figure 3.31 ▪ Purpura Fulminans.

Purpura fulminans is a cutaneous infarction and/or acral gangrene due to DIC. It can be seen in any overwhelming bacterial sepsis. Lesions of purpura fulminans are usually seen at the distal extremities, areas of pressure, and lips, ears, nose, and trunk. (Photo contributor: Binita R. Shah, MD.)

Advise chemoprophylaxis for close contacts (risk of contracting meningococcal infection among close contacts is 500 to 800 times the rate for the general population). Throat and nasopharyngeal cultures are of no value for deciding who should receive prophylaxis. Antibiotic prophylaxis is given within 24 hours of diagnosis of primary case. Chemoprophylaxis options include rifampin (drug of choice for children) or ceftriaxone, and rifampin, ceftriaxone, or ciprofloxacin for adults. Refer to the American Academy of Pediatrics Red Book for details of dosing and categories of “close contacts.” Health care workers who did not have direct exposure to the patient’s oral secretions do not need to panic, and they do not need chemoprophylaxis.

Pearls

N meningitidis has become the leading cause of bacterial meningitis in children as vaccination for H influenzae, type b, and S pneumoniae has become available.
A transient maculopapular rash mimicking a wide variety of viral exanthems may be a presenting sign of meningococcemia. Conduct a careful examination of skin and mucous membranes for petechiae (a common harbinger of meningococcemia).
Classic signs of meningococcal infection (fever with petechiae or purpura) are seen in only 70% of cases. Patients with meningococcal meningitis may also lack CSF abnormalities on initial LP (even with a positive CSF culture). Thus, infections by N meningitidis must be considered even in the absence of skin lesions or CSF abnormalities.

Figure 3.32 ▪ Henoch-Schönlein Purpura; Differential Diagnosis of Meningococcemia.

Symmetrically distributed palpable purpuric lesions on both lower extremities and buttocks (usually below the waist) are characteristic features of HSP. Other associated findings (eg, arthralgia/arthritis, abdominal pain, hematuria) also help in differentiating HSP from meningococcemia. Patients with HSP are also usually afebrile and not sick-looking and the platelet count is usually elevated or normal. (Photo contributor: Binita R. Shah, MD.)

Figure 3.33 ▪ Petechiae from Other Etiology; Differential Diagnosis of Meningococcemia.

Sudden eruption of petechiae associated with subconjunctival hyperemia appeared only on the face in this afebrile girl following several violent episodes of vomiting due to food poisoning. The remainder of her examination was normal. Petechiae on the face and upper thorax can occur in healthy children following intractable episodes of coughing or vomiting. In contrast, meningococcal infections would cause generalized distribution of petechiae. (Photo contributor: Binita R. Shah, MD.)

Rocky Mountain Spotted Fever

Clinical Summary

Rocky Mountain Spotted Fever (RMSF) is an acute febrile exanthematous illness caused by Rickettsia rickettsii, which are transmitted by either dog tick, wood tick, or Lone Star tick, which are systemically infected, and transmit it to humans while feeding. RMSF is the second most common (after Lyme disease) tick-borne infection in the United States. RMSF is a misnomer; cases are reported from all parts of the United States. Risk factors include exposure to dogs, residence in wooded areas, and male gender. The tick bite is painless and often goes unrecognized. About 60% of cases are preceded by the removal of an attached and engorged tick. Incidence is highest in children aged 5 to 9 years and during the months of April to October. The incubation period ranges from 2 to 14 days, and there may be a prodrome of nonspecific symptoms (mimics viral infection). Classically, patients present with severe headache, myalgia, and bilateral calf pain and may have photophobia, abdominal pain, vomiting, and diarrhea, with abrupt onset of fever and chills. The rash occurs 2 to 4 days after the onset of illness beginning on wrists and ankles and spreading to extremities and trunk within 24 hours; the palms and soles are nearly always affected. Rash begins as erythematous maculopapular lesions that blanch on pressure and becomes petechial and may become confluent with areas of necrosis. The severity of the rash varies from mild evanescent to severe generalized. Involvement of the scrotum and vulva is a diagnostic clue. Desquamation may be seen in severe areas. Conjunctivitis, lymphadenopathy, hepatosplenomegaly, jaundice, periorbital or peripheral edema may also be present.

Figure 3.34 ▪ Rocky Mountain Spotted Fever (RMSF).

(A, B, C) Erythematous maculopapular eruption that started on the distal extremity and subsequently became petechial associated with fever, severe headache, and myalgia were seen in this adolescent boy. A history of camping during summer vacation in North Carolina 12 days before onset of this rash was obtained. These photographs were taken on the fifth day of the illness. As seen here, the palms and soles are nearly always affected in RMSF. He also had edema of both hands and feet. (Photo contributor: Binita R. Shah, MD.)

Differential diagnosis of RMSF includes meningococcemia, bacterial sepsis from other pathogens (eg, S pneumoniae), Henoch-Schönlein purpura, maculopapular rash from viral exanthems (eg, echovirus, Epstein-Barr virus), toxic shock syndrome, idiopathic thrombocytopenic purpura, measles or atypical measles, drug-induced hypersensitivity reactions (eg, sulfonamides, penicillins), secondary syphilis, and Kawasaki disease.

Emergency Department Treatment and Disposition

Obtain CBC (a normal or low WBC with bandemia, thrombocytopenia, anemia), comprehensive metabolic panel (hyponatremia, hypoalbuminemia, elevated serum values of CPK, and liver enzymes may be seen). If clinically indicated, perform lumbar puncture (CSF exam may be normal or show pleocytosis with an elevated protein and normal glucose values). Obtain specific serologic antibody titers (a fourfold or greater rise in titer between the acute and convalescent phases are diagnostic; however, it takes 7 to 10 days into the course of illness to yield results). RMSF is a curable but potentially fatal disease. An important factor in patient survival is early diagnosis and therapy. Admit critically ill patients after stabilization of vital signs, including restoration of fluid and electrolyte abnormalities. Begin empiric therapy with IV doxycycline (drug of choice) and a third-generation cephalosporin to cover for N meningitidis. Other alternative includes tetracycline (for patients >8 years of age; tetracycline staining of teeth is dose-related; doxycycline is less likely to cause dental staining than other tetracyclines). Consult dermatology if diagnosis is unclear. Diagnosis of RMSF can be confirmed rapidly (usually between 4 and 8 days) in patients with a rash. Immunofluorescent staining or PCR of skin biopsy samples demonstrate R rickettsii. For the removal of a tick, grasp the tick with fine tweezers close to the skin and pull gently straight out without twisting. If fingers are used, protect them with tissue and avoid squeezing the body of the tick followed by thoroughly washing hands after removal.

Figure 3.35 ▪ Meningococcemia; Differential Diagnosis of Rocky Mountain Spotted Fever (RMSF).

Purpura with septic shock was the presentation of this adolescent girl. Differentiation between RMSF and meningococcemia is difficult based on clinical presentation alone. (Photo contributor: Vania Kasper, MD.)

Figure 3.36 ▪ Henoch-Schönlein Purpura (HSP); Differential Diagnosis of Rocky Mountain Spotted Fever (RMSF).

Symmetrically distributed palpable purpuric lesions on both lower extremities and buttocks (usually below the waist) are characteristic features of HSP. Patients with HSP are also usually afebrile, not sick-looking like those with RMSF, and the platelet count is usually elevated or normal. (Photo contributor: Anup Singh, MD.)

Pearls

Centripetal spread is the hallmark, with rash first appearing on wrists and ankles followed by spreading to trunk within hours.
The classic triad of fever, rash, and history of tick bite is present in only 60% to 70% of patients. Neither absence of tick exposure nor absence of rash excludes the diagnosis. A “spotless” form of RMSF occurs in approximately 5% of children infected with R rickettsii.
The most significant risk factor for death is a delay of appropriate antibiotic therapy; do not withhold therapy while awaiting confirmation by the serology tests.
Differentiation between RMSF and meningococcemia is difficult based on clinical presentation alone.

Cat-Scratch Disease

Clinical Summary

Cat-scratch disease (CSD) is a zoonotic bacterial infection caused by Bartonella henselae following a cat scratch (especially kittens or feral cats). Infection is transmitted by cutaneous inoculation. Transmission between cats occurs by the cat flea. Most reported cases occur in people aged <20 years. A history of a recent contact with a cat is present in >90% of cases. Even though many siblings may play with the same kitten, only one family member is usually affected. Occasionally clusters of CSD may be seen in the same family within weeks of one another. The incubation period is 7 to 12 days (from time of scratch to appearance of skin papule) or 5 to 50 days (skin lesion to regional lymphadenopathy). There may be visible signs at the inoculation site, including a scratch or bite with one or more small red papules or pustules, though this is often overlooked because of small size. Typically patients present with regional lymphadenopathy of 1 to 5 cm or more and is the most prominent and common symptom, occurring in >90% of cases. Low-grade fever and other constitutional symptoms (eg, malaise, anorexia, fatigue, headache) may be present. Usually, there is involvement of a single lymph node that drains the inoculation site, though occasionally multiple lymph nodes are involved. The most commonly involved sites are axilla, cervical, submandibular, preauricular, epitrochlear, femoral, and inguinal lymph nodes. The nodes are tender, warm, erythematous, and indurated and the lymphadenopathy usually lasts 1 to 2 months, but can last up to 1 year. Spontaneous suppuration is seen in 10% to 40% of cases.

Figure 3.37 ▪ Cat-Scratch Disease.

Axillary lymphadenitis (with tenderness, erythema and warmth) of 3 weeks’ duration is shown in a 4-year-old child who received a kitten as a Christmas gift 2 months before the onset of this swelling. He gave a history of playing roughly and receiving several scratches on his arm by the kitten. A needle aspiration was performed to relieve the symptoms (usually needle aspiration of suppurative nodes is preferred over I & D to avoid prolonged drainage and possible scarring). (Photo contributor: Binita R. Shah, MD.)

Figure 3.38 ▪ Bacterial Adenitis/Abscess; Differential Diagnosis of Cat-Scratch Disease.

Axillary lymphadenitis (tenderness, erythema, and warmth) and fever of 3 days’ duration were the presenting complaint of this child who was prescribed dicloxacillin. An abscess developed requiring I & D and culture was positive for Staphylococcus aureus. (Photo contributor: Binita R. Shah, MD.)

In atypical CSD, there is Parinaud oculoglandular syndrome (involvement of conjunctiva with granuloma but without any discharge or pain, involvement of ipsilateral preauricular lymph node, and may involve ipsilateral submandibular or cervical lymphadenopathy).

Rare manifestations of CSD include persistent fever, skin rashes (eg, erythema nodosum, maculopapular rashes), aseptic meningitis, encephalitis, hepatitis, pneumonia, microabscess in liver and spleen, osteolytic lesions, and thrombocytopenic purpura. Differential diagnosis of unilateral lymphadenopathy includes bacterial adenitis, viral infections (eg, infectious mononucleosis), malignancy (eg, lymphoma), typical or atypical mycobacterial infection, tularemia, brucellosis, histoplasmosis, toxoplasmosis, and lymphogranuloma venereum.

Emergency Department Treatment and Disposition

Consult infectious disease specialist for advice on diagnostic tests (eg, indirect fluorescent antibody test for detection of serum antibody to antigens of Bartonella species or polymerase chain reaction assay) and management. Consider ultrasonography for assessing lymph nodes’ size and suppuration. CSD is a self-limited infection and management is primarily symptomatic. Lymphadenopathy may persist for 2 to 4 months, but spontaneous resolution is the rule. Consider direct needle aspiration of pus to relieve discomfort with suppurative nodes; avoid incision and drainage (I & D). Consider antibiotic therapy for ill patients with systemic symptoms (eg, patients with large painful adenopathy or immunocompromised hosts). Choices include oral (eg, azithromycin, trimethoprim-sulfamethoxazole, ciprofloxacin) and parenteral antibiotics (eg, gentamicin). Educate families that cats are usually healthy and require no treatment, no need to get rid of the cat and on prevention of CSD (eg, avoid playing roughly with cats/kittens, declawing, careful hand washing after handling the cat, immediately washing sites of cat scratches/bites and not allowing cats to lick open cuts or wounds).

Pearls

Chronic regional lymphadenitis is the hallmark of CSD.
Consider CSD in patients with adenopathy, fever, malaise, and history of a feline contact.

Chickenpox

Clinical Summary

Chickenpox or varicella is an acute exanthematous illness caused by varicella-zoster virus (VZV), carried only by humans and spread by person-to-person contact or airborne droplets of infected respiratory tract secretions. Maternal varicella infection can lead to transplacental in utero infection. Incubation period is 10 to 21 days (less in the immunocompromised) and there is usually no prodrome in children. Rash and constitutional symptoms (eg, low-grade fever, headache) occur simultaneously and the rash lasts 5 to 7 days (longer in immunocompromised and may become hemorrhagic). The rash is vesicular with centripetal distribution, involving the scalp and mucous membranes (eg, conjunctiva, oropharynx). Lesions are round or oval and progress from macule to papule to vesicle to pustule, followed by crusting; different stages of lesions can be seen together in the same anatomic area (unlike smallpox). Central umbilication of lesions occurs with healing. Children receiving intermittent courses of corticosteroids (eg, for asthma) may have more severe course. Differential diagnosis of other papulovesicular eruptions includes herpes zoster, coxsackie virus infections (eg, hand-foot-and-mouth disease), drug eruptions (eg, Stevens-Johnson syndrome), eczema herpeticum, eczema vaccinatum, rickettsialpox, bullous impetigo, impetigo contagiosum, arthropod bites/papular urticaria, dermatitis herpetiformis, and smallpox.

Figure 3.39 ▪ Chickenpox.

(A, B) These figures show the presence of lesions in different stages (papule, vesicle, pustule, and crusted lesion) with a centripetal distribution in a child with chickenpox. Lesions are also seen on mucous membranes involving the lips and oropharynx. (Photo contributor: Binita R. Shah, MD.)

Complications (more common in immunocompromised) include secondary skin infections by S aureus and/or S pyogenes (eg, cellulitis, impetigo); streptococcal TSS; necrotizing fasciitis; CNS (eg, meningoencephalitis, cerebellar ataxia), cardiac (eg, myocarditis), hematologic (eg, acute thrombocytopenia, hemorrhagic chickenpox), renal (eg, glomerulonephritis), and bone (eg, reactive arthritis), bronchopneumonia; and hepatitis.

Emergency Department Treatment and Disposition

Diagnosis is clinical. Laboratory tests (eg, Tzanck smear, polymerase chain reaction, or direct fluorescent antibody test to identify VZV from vesicular fluid) are rarely required. Chickenpox is a benign, self-limiting disease in otherwise healthy children, and oral acyclovir is not recommended for routine use. Acyclovir (given within 24 hours of onset of rash) can be considered in those at increased risk for moderate to severe varicella (eg, patients >12 years of age; patients receiving either long-term salicylates or short, intermittent, or aerosolized courses of corticosteroids; and patients with chronic cutaneous or pulmonary disorders). Chickenpox is highly contagious (most contagious from 1 to 2 days before the onset of rash until all the lesions have dried or crusted). Secondary cases occur in 98% of susceptible persons when exposed. Varicella-zoster immune globulin (VeriZIG for passive immunoprophylaxis) is recommended (given within 96 hours of exposure) for contacts at risk of developing severe varicella. Refer to American Academy of Pediatrics Red Book for recommendations on antiviral therapy and VeriZIG. Admit immunocompromised patients for IV antiviral therapy. Do not prescribe salicylates (or salicylates-containing products) to children with varicella (association with Reye syndrome). Consider colloidal oatmeal baths and antipruritic lotions like pramoxine for the pruritus and discomfort. Be careful when prescribing antipruritic medications that cause drowsiness, as this side effect may mask lethargy and drowsiness related to complications of chickenpox (eg, meningoencephalitis).

Figure 3.40 ▪ Chickenpox.

Appearance of chickenpox is sometimes described as “dew drops on a rose petal”; the classic vesicles are surrounded by erythema. (Photo contributor: Binita R. Shah, MD.)

Figure 3.41 ▪ Bullous Varicella.

Intact pus-filled bullae resulting from secondary infection with Staphylococcus aureus were seen on the trunk of a child with chickenpox. Close-up of pus-filled bullous lesion is shown. (Photo contributor: Binita R. Shah, MD.)

Pearls

Varicella-zoster virus remains in a latent state in the dorsal root ganglion cells, and may get reactivated (as the immunity wanes), resulting in herpes zoster.
Chickenpox is more severe in adolescents, adults, and immunocompromised hosts.

Herpes Zoster

Clinical Summary

Herpes zoster or shingles is an acute vesiculopustular eruption occurring in dermatomal distribution caused by varicella-zoster virus (VZV) and is unusual in children.

A prior clinical or subclinical episode of varicella is a prerequisite for the occurrence of herpes zoster. After primary infection has occurred, the virus lies dormant in a sensory ganglion; reactivation of the latent virus results in herpes zoster. Up to 20% of those with history of varicella develop herpes zoster during their lifetime, and multiple attacks can occur (eg, HIV patients). Young infants may develop herpes zoster without prior clinical varicella if in utero exposure occurred. Zoster begins with pain and tingling within the dermatome and progresses to sharp, dull, or burning pain, which precedes the rash by 48 to 72 hours (range 1–10 days). Pain is minimal when zoster occurs in children and there is usually a lack of systemic symptoms. The rash begins as erythematous macules and papules that progress to vesicles (12–24 hours) to pustules (3–4 days), then crusting (7–10 days). Vesicles are grouped and umbilicated on an erythematous base in a linear distribution, and erupt along one to three dermatomes supplied by a spinal or cranial nerve (most common site: thoracic T5-T10 [˜75% of cases]). Lesions do not cross the midline in immunocompetent hosts.

Figure 3.42 ▪ Herpes Zoster.

Herpes zoster involving the T5 dermatome. Lesions do not cross the midline in an immunocompetent child. (Photo contributor: Binita R. Shah, MD.)

Figure 3.43 ▪ Herpes Zoster.

An 8-month-old infant with herpes zoster on C5 and C6 dermatomes. This infant never had chickenpox, but his mother had varicella during the last trimester of pregnancy. (Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 55.)

Ramsay Hunt syndrome is a specific manifestation of zoster that affects geniculate ganglion (facial or auditory nerves) and involves the pinna, auditory canal, tympanic membrane, and anterior two-thirds of the tongue (decreased taste). Patients present with ipsilateral Bell palsy, tinnitus, deafness, vertigo, hearing loss, and otalgia. In herpes zoster ophthalmicus, the ophthalmic branch of the trigeminal nerve is affected and rashes occur on the eyelids; in addition, conjunctivitis, keratitis, iridocyclitis, secondary glaucoma, ocular muscle palsies, ptosis, mydriasis, and panophthalmitis may occur. Hutchinson sign (involvement of nasociliary division of ophthalmic nerve with vesicles on the side and top of the nose) may be seen. Vesicles occur on the palate, uvula, and tonsillar fossa when the maxillary branch of the trigeminal nerve is involved and on the buccal mucosa, floor of the mouth, and anterior part of the tongue when the mandibular branch is involved. Disseminated zoster (generalized rash with fever) and visceral dissemination (pneumonia, hepatitis, meningoencephalitis) may be seen in patients with persistent depression of cell-mediated immunity. CNS involvement may occur and includes asymptomatic CSF lymphocytic pleocytosis with normal or elevated protein value or symptomatic meningoencephalitis (eg, headache, vomiting, photophobia, altered sensorium), transverse myelitis, and zoster paresis (motor weakness and atrophy in associated myotome). Postherpetic neuralgia (pain persisting for >6 weeks after disappearance of the rash) is uncommon in children. Differential diagnosis includes dermatomal herpes simplex infections (eg, anogenital herpes), contact dermatitis, grouped arthropod bites, and localized bacterial or viral skin infections.

Figure 3.44 ▪ Herpes Zoster.

(A, B, C) Vesicular eruptions were present on the face, lips, anterior two-thirds of the tongue, pinna, auditory canal, and tympanic membrane of this girl. She did not have facial nerve palsy. Note that lesions do not cross the midline. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical. Laboratory tests (eg, Tzanck smear, polymerase chain reaction, or direct fluorescent antibody test to identify VZV from vesicular fluid) are rarely required. Admit immunocompromised patients for IV antiviral therapy and observe airborne/contact precautions for duration of the illness. Immunocompetent children usually do not need any treatment and can be discharged with instructions to wash hands after touching lesions and cover lesions. If lesions cannot be covered, instruct caregivers to keep them home from school/daycare until lesions are crusted. Consult ophthalmology for patients with zoster ophthalmicus.

Pearl

A patient with herpes zoster can transmit varicella, but not herpes zoster, to a susceptible host.

Oropharyngeal Herpes Simplex Virus Infection

Clinical Summary

Oropharyngeal herpes simplex virus (HSV) infections manifest as acute herpetic gingivostomatitis, herpes labialis or pharyngitis. Type 1 infections usually occur above the waist and type 2 usually below the waist; HSV-1 or HSV-2 can be found in either site, depending on the source of infection. Transmission is by skin-to-skin, mucosa-to-mucosa, or skin-to-mucosa contact. Most primary HSV infections are asymptomatic and virus persists for life in a latent form in a sensory ganglion. Reactivation may follow several triggers, including febrile illness, emotional or physical stress, debilitating activities. In adolescents, primary HSV manifests as pharyngitis (shallow tonsillar ulcers with or without gray exudates).

Gingivostomatitis commonly affects children aged 1 to 3 years, who present with high fever, foul breath, inability to eat or drink, dehydration, drooling, and irritability. Lesions begin as vesicles that rapidly rupture turning into shallow gray ulcers (1–3-mm size) on an erythematous base. The ulcers are extremely painful, friable, and bleed easily. The gums are swollen, ulcerated, erythematous, friable, and bleed easily; gingivitis may precede appearance of mucosal vesicles. Lesions are typically located on the anterior tongue, buccal mucosa, gums, hard and soft palate; lesions may extend to lips, chin, or neck (even in an immunocompetent child). Tender cervical and submandibular/submental lymphadenopathy may be present. Gingivostomatitis is self-limited and usually resolves in 5 to 7 days.

Herpes labialis or fever blisters have a prodrome of pain, burning, tingling, or itching that lasts a few hours; systemic symptoms are unusual. The lesions begin within 24 to 48 hours after prodrome as papule progresses to vesicle to ulcer followed by crusting (within 3 to 4 days) and healing (within 5 to 10 days). The lesions are painful, especially at the vesicular stage, and are typically found at the vermilion border of lips, mucocutaneous junction of the perioral region; lesions are localized in a nondermatomal distribution and recur at the same location or closely adjacent areas.

Differential of gingivostomatitis and herpes labialis includes herpangina, hand-foot-and-mouth disease, aphthous stomatitis (recurrent ulcers with rim of erythema and gray exudates), and zoster ophthalmicus. Differential of herpes pharyngitis includes acute exudative tonsillopharyngitis from other etiologies (eg, S pyogenes, adenovirus, Epstein-Barr virus).

Figure 3.45 ▪ Recurrent Herpes Labialis and Recurrent Erythema Multiforme (EM).

(A) HSV is the most common etiology of EM and recurrences of EM are common with recurrences of HSV infections. (B) Typical annular erythematosus lesions (target lesions) with duskiness in the center are seen on the face of this child who had herpes labialis (drying HSV lesions seen around the lower lip) 5 days prior to the onset of EM. (Photo contributor: Binita R. Shah, MD.)

Figure 3.46 ▪ Herpes Labialis.

(A) The hallmark of herpes simplex virus skin infections is grouped vesicles on an erythematous base as seen here on the mucocutaneous junction of the lip. (B) Recurrent herpetic lesions in a patient with HIV infection. The lesions began with vesicles and healed with crusting. This patient also had lesions on the tongue and buccal mucosa. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical and tests are usually not required. Tzanck smear is positive in both HSV and varicella zoster virus (VZV) infections. Culture of fluid from vesicles or scrapings of the lesion or polymerase chain reaction assay will differentiate between HSV and VZV infections when necessary. Admit immunocompromised patients for IV antiviral therapy (refer to American Academy of Pediatrics Red Book guidelines). For immunocompetent patients, antiviral therapy is not routinely recommended. Advise supportive therapy including antipyretics, hydration, and dietary modifications (eg, cool drinks, popsicles, and soft diet; avoid citrus juices). Do not prescribe oral anesthetics (eg, lidocaine viscous) because of the risk of toxicity via absorption through oral mucosa. Exclude children with gingivostomatitis with drooling and active lesions from child care centers.

Figure 3.47 ▪ Herpetic Gingivostomatitis.

A child presenting with high fever, refusal to eat, and sores in the mouth. (Photo contributor: Binita R. Shah, MD.)

Pearls

In children, most common manifestation of primary HSV infection is gingivostomatitis, and of recurrent HSV infection is herpes labialis.
Recurrent HSV infections may be associated with recurrent episodes of erythema multiforme.
Herpetic gingivostomatitis may be confused with herpangina. Vesicles are usually not seen on the buccal mucosa and anterior portion of the mouth in herpangina.

Figure 3.48 ▪ Tzanck Smear of Herpetic Infection.

Giemsa stain of vesicle contents demonstrating multinucleated giant cells (fused virally infected keratinocytes) is indicative of a herpetic infection. (Reproduced with permission from: Kane KS, Ryder JB, Johnson RA, et al. Herpes simplex virus. In: Color Atlas & Synopsis of Pediatric Dermatology. New York, McGraw-Hill, 2002, p. 544.)

Herpetic Whitlow

Clinical Summary

Herpetic whitlow is a cutaneous HSV infection of the terminal phalanx of the fingers or thumb. It is an occupational hazard (eg, dentists) that may also occur in infants and young children; first episode may accompany herpetic gingivostomatitis. After the primary infection, HSV remains dormant in the sensory ganglia and can recur in the same location. Onset is abrupt with pain or paresthesia at the site. Skin lesion begins as groped vesicles and/or pustules on an erythematous base, subsequently becoming a painful, erythematous, swollen lesion that usually persists for 7 to 10 days (range, 1–3 weeks). Common sites are terminal phalanx of finger or thumb. One or more fingertips may be involved. Fever, lymphangitis, and regional lymphadenopathy may accompany the lesion. Differential diagnosis includes contact dermatitis and dyshidrotic eczema.

Figure 3.49 ▪ Herpetic Whitlow.

A 4-month-old infant presenting with clusters of vesiculopustular lesions on an erythematous base on the finger. This infant’s mother had “cold sores” 7 days prior to developing this rash. Culture of the lesion was positive for HSV-1. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical. Tzanck smear (see Figure 3-48) or a needle aspiration of the lesion for HSV culture will confirm the diagnosis. It usually resolves without any specific therapy. Supportive therapy includes antipyretics and analgesics for pain as indicated. Topical penciclovir cream may be applied to affected areas every 2 hours. Acyclovir may be used for severe infections.

Pearls

Herpetic whitlow is characterized by grouped umbilicated, vesiculopustular lesions on an erythematous base on the distal fingertips or thumb. It is commonly confused with a bacterial paronychia or felon.
Do not incise or drain herpetic whitlow; surgical débridement may exacerbate the condition.

Figure 3.50 ▪ Herpetic Whitlow.

Herpes simplex virus infection like this often gets mistaken for paronychia. (Photo contributor: Binita R. Shah, MD.)

Mumps

Clinical Summary

Mumps is an acute systemic paramyxovirus infection characterized by swelling of the parotid and other salivary glands. History of exposure to a similar illness is important as humans are the only known natural hosts and the virus is acquired by direct intimate contact with oropharyngeal secretions (droplets). Incubation period ranges from 12 to 25 days after exposure. There is a 1 to 2-day prodrome of fever, headache, malaise, anorexia, and abdominal pain. Bilateral (70% of cases) or unilateral painful, nonerythematous parotid gland swelling follows. This pushes the ear lobe upward and outward, obscuring the mandibular angle. The opening of Stensen duct may be red and edematous. Ingestion of sour liquids may increase pain in the parotid gland. Submaxillary glands may be involved as well. Symptoms occur with (or closely follows) parotitis. Rarely, only submaxillary glands are involved. The opening of Wharton duct may be red and edematous. Sublingual glands are least frequently involved, and bilateral swelling is seen in the submental region and in the floor of the mouth.

Complications include CNS involvement (eg, meningitis or encephalitis), orchitis or epididymo-orchitis (seen among postpubertal adolescents and young adults). Other rare complications include arthritis, oophoritis, cerebellar ataxia, transverse myelitis, pancreatitis, myocarditis, and deafness. Differential diagnosis of mumps parotitis includes parotitis from other viruses (eg, HIV, parainfluenza, or coxsackie viruses), bacterial parotitis (eg, S aureus), lymphadenitis (eg, anterior cervical or preauricular adenitis) and other causes of parotid swelling (eg, sarcoidosis, parotid duct stone, and long-term wind instrument use). Differential diagnosis of mumps orchitis includes epididymo-orchitis from other etiology (eg, sexually transmitted diseases), and testicular torsion (especially when orchitis precedes parotitis). Differential diagnosis of mumps meningoencephalitis includes meningoencephalitis from other viruses (eg, enterovirus).

Figure 3.51 ▪ Parotitis.

(A) Mumps. Parotid swelling in an unimmunized child who immigrated from Trinidad 14 days before the appearance of this swelling. The parotid gland is normally not palpable. Note swelling extending below the angle of the mandible. (B) Human immunodeficiency virus parotitis. Children with HIV can develop parotitis usually without much symptoms. Typically, the parotid gland is firm, nontender, and chronically enlarged. Involvement can be unilateral or bilateral. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical and no laboratory tests are usually required. Serum amylase is elevated in approximately 70% of cases of parotitis, with peak values during the first week of illness. Treatment is supportive for the majority. Resolution of parotitis takes approximately 10 days. Prescribe support of the testicle, ice packs, and pain management for mumps orchitis with follow-up. Admit patients with meningitis (or meningoencephalitis) for supportive management. Mumps is contagious; exclude children from school for 5 days from onset of parotid gland swelling. Advise standard as well as droplet precautions for contagious illness.

Pearls

Mumps presents as either unilateral or bilateral mildly tender parotid gland swellings.
Purulent parotitis is unilateral; extremely tender and purulent drainage from Stensen duct may be noted.

Roseola Infantum

Clinical Summary

Roseola infantum (also known as exanthem subitum, or roseola or sixth disease) is an acute exanthematous illness caused by human herpesvirus-6 (HHV-6; majority of cases) or HHV-7, for which humans are the only known natural hosts. Infants may have apparent recurrence that is actually sequential infection by the two viruses. Roseola cases occur throughout the year without any seasonal predilection. About 95% of cases occur at 6 to 36 months of age (peak: between 6 and 15 months). The incubation period is 7 to 15 days. Usually there is no prodrome or mild rhinorrhea and pharyngeal and conjunctival injection. Illness begins with an abrupt-onset fever that rises rapidly to 39°C to 41°C and remains elevated consistently or intermittently for 3 to 6 days, after which time it drops precipitously. Most infants look well during the febrile period though there may be a bulging anterior fontanelle and lymphadenopathy (cervical, occipital). After the fever drops (12–24 hours) and rarely as it is dropping, a rash of pink- to rose-colored nonpruritic macules or maculopapules occurs on the trunk and then spreads to the face and extremities. Lesions blanch on pressure and do not become vesicular, pustular, or petechial. Lesions usually remains discrete and the rash is evanescent, lasting from a few hours to 1 to 3 days, after which it clears completely without pigmentation or desquamation. CNS complications include febrile seizures during the febrile prodromal stage (seen in 10%–15% of cases), meningoencephalitis, or encephalitis. Differential diagnosis includes other viral infections (eg, enteroviral infections, infectious mononucleosis, and rubella), drug hypersensitivity reactions, and Kawasaki disease.

Figure 3.52 ▪ Roseola Infantum.

Diffuse erythematous maculopapular eruptions that developed after 3 days of intermittently high fever (up to 40°C) in this well-appearing 8-month-old infant who was hospitalized because of bulging fontanelle. All the cultures were negative including CSF. A diagnosis of roseola infantum was made when he developed this rash. Note the absence of conjunctival injection and red lips (characteristic features that are often seen in a highly febrile infant with Kawasaki disease). (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis of roseola is clinical based on the age, classic history, and clinical findings. During the eruptive phase, no laboratory tests are required as classic roseola is rarely confused with other viral exanthems, and a specific diagnosis of HHV-6 is not usually necessary. During the preeruptive, highly febrile stage of roseola, many infants undergo sepsis workup, receive antibiotic therapy awaiting culture results, and even hospitalization (especially infants presenting with a bulging anterior fontanelle). CSF examination in infants with HHV-6-associated febrile seizures is usually normal. A diagnosis of roseola is often established in these infants retrospectively when they develop the rash. No therapy is required during this stage except reassuring the family about the benign course of roseola.

Pearls

Roseola is the most common exanthem of infants <2 years of age.
The sine qua non of roseola is appearance of rash at defervescence; thus, roseola often gets diagnosed retrospectively once the typical febrile course has been observed, followed by appearance of the rash at defervescence.
Roseola is frequently misdiagnosed as drug hypersensitivity rash, as these infants are frequently prescribed antibiotics during the febrile preeruptive phase. Detailed history of rash in relation to fever will establish the correct diagnosis.

Figure 3.53 ▪ Roseola Infantum.

Diffuse erythematous maculopapular eruption that developed after 4 days of high fever in this very happy-looking 18-month-old toddler. He was treated for occult bacteremia as an outpatient. He continued to spike fever in spite of antibiotic therapy and blood and urine cultures were negative. He was rushed to the ED when this rash appeared on the fifth day (he was afebrile). A diagnosis of roseola infantum was made (Important: A toddler should not be eating raisins due to the risk of choking and foreign body aspiration) (Photo contributor: Binita R. Shah, MD.)

Measles

Clinical Summary

Measles (also known as Rubeola or first disease) is a highly contagious exanthematous illness caused by a paramyxovirus. The incubation period is 8 to 12 days and there is a prominent prodrome of fever, cough, coryza, conjunctivitis (the 3 C’s) with significant photophobia. On the third day of illness, erythematous maculopapular lesions occur along the hairline and spread down the trunk and extremities to the hands and feet, involving palms and soles. On the face and trunk, the rash becomes confluent and initially blanches on pressure; after 3 to 4 days the rash becomes brownish and does not blanch because of capillary hemorrhages. The rash peaks at the height of fever between the fourth and sixth day of illness and resolves in order of appearance between the seventh and ninth day. Following the rash, a fine, brawny desquamation is seen over sites of most extensive involvement (but not on palms or soles, differentiating it from scarlet fever and Kawasaki disease). Koplik spots are a pathognomonic mucocutaneous exanthem of white papular dots on an erythematous buccal mucosa seen opposite lower molars that may spread to involve entire buccal and labial mucosa. Koplik spots are seen 2 days before and 2 days after the rash and are transient. Absence of Koplik spots does not exclude diagnosis. Modified measles is milder (eg, afebrile course, nonconfluent rash with shorter duration) in infants <9 months old because of a transplacental antibody or administration of immunoglobulin to an exposed individual. Complications include otitis media, pneumonia (interstitial pneumonitis from measles virus or bronchopneumonia from secondary bacterial infection), cervical adenitis, encephalomyelitis, laryngotracheobronchitis, myocarditis, pericarditis, exacerbation of tuberculosis, “black” measles (hemorrhagic measles, purpura fulminans with disseminated intravascular coagulation), corneal ulceration, and blindness. Differential diagnosis includes Kawasaki disease, drug eruptions (eg, Stevens-Johnson syndrome), meningococcemia, rickettsial infections, other viral exanthems (eg, adenovirus, infectious mononucleosis, and enteroviruses).

Figure 3.54 ▪ Measles.

(A, B, C) An 8-month-old child presented with fever, coryza, and marked conjunctivitis associated with intense photophobia. Confluent, erythematous, and maculopapular rash on the face developed on the fourth day of fever. He developed measles during the measles outbreak seen in New York City in 1993. (Photo contributor: Binita R. Shah, MD [A, B]; Photo C. Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 61.)

Figure 3.55 ▪ Koplik’s Spots of Measles.

White spots on the hard palate of a patient with measles. (Reproduced with permission from: Mei Kane KS, Ryder JB, Jonson RA et al: Measles virus. In: Color Atlas & Synopsis of Pediatric Dermatology. New York, McGraw-Hill, 2002, p. 585.)

Emergency Department Treatment and Disposition

Diagnosis is usually clinical. Report case immediately to the local health department for assistance in verifying the diagnosis. Serum IgM antibody to measles is one of the simplest methods to confirm diagnosis. Additional tests (eg, measles IgG antibody acute and convalescent titers) may be recommended. Obtain CBC (leukopenia with a relative lymphocytosis seen in uncomplicated measles). CSF examination in suspected encephalitis will show mild pleocytosis with predominance of lymphocytes with increased protein and normal glucose values. Admit infants, malnourished children, or patients with complications (eg, pneumonia, croup, encephalitis). Measles is self-limiting, and treatment is supportive. Patients are contagious from 3 to 5 days before to 4 days after the appearance of the rash. Immunocompromised patients are contagious for the duration of the illness (prolonged excretion of the virus in respiratory tract secretions). Vitamin A therapy has been associated with a reduction in morbidity and mortality. Currently, the World Health Organization recommends vitamin A for all children with acute measles, regardless of their country of residence. Follow CDC guidelines for administration of the vaccine and immune globulin (IG) in susceptible individuals following exposure to measles.

Pearls

Measles is characterized by a prominent prodrome of cough, coryza, and conjunctivitis (the 3 C’s) followed by confluent erythematous maculopapular rash.
Immunocompromised children may not develop characteristic rash.

Rubella

Clinical Summary

Rubella (also known as German measles or three-day measles) is an exanthematous infection caused by rubella virus. Humans are the only source of infection, which is transmitted through direct or droplet contact from nasopharyngeal secretions. Many cases are subclinical; clinical cases are mild and now seen in susceptible teenagers and young adults. Incubation period varies from 14 to 21 days. Coryza, cough, conjunctivitis (without photophobia) and sore throat may occur in adolescents. In children, the prodrome is absent and rash is the first sign of illness. Fever is absent or low-grade during rash (unlike measles). Palatal enanthem (petechiae or rose spots) may be seen. Rose-pink maculopapular rash starts on the face and neck, becoming generalized within 24 to 48 hours. Lesions are discrete (unlike striking confluent rash of measles). By the third day, rash on the face disappears and is present only on the extremities. Eruption usually resolves by the end of the third day, followed by fine brawny desquamation (with intense eruption) or no desquamation. Tender lymphadenopathy involving postauricular and suboccipital nodes occurs (most common sites), but can be generalized. Complications include transient polyarthralgia and polyarthritis in adolescent females, purpura (thrombocytopenic or nonthrombocytopenic purpura), and congenital rubella syndrome. Differential diagnosis includes other viral exanthems (eg, infectious mononucleosis, enteroviral infections) and drug eruptions.

Figure 3.56 ▪ Congenital Rubella Syndrome (CRS).

An infant with glaucoma, microcephaly, and patent ductus arteriosus was born to an unimmunized mother who contracted rubella during the first trimester of pregnancy. Other eye findings of CRS include cataract, anterior uveitis, and micro-ophthalmia. (Photo contributor: Binita R. Shah, MD.)

Figure 3.57 ▪ Rubella.

(A, B) Discrete erythematous rose-pink papular rash over the face and subsequently spreading to the trunk in an otherwise well-appearing 16-month-old infant who was not immunized for rubella. The patient also had significant postauricular and suboccipital adenopathy. Adenovirus and enterovirus infections can cause exanthema that mimics rubella. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Rubella is a difficult clinical diagnosis as similar rash is seen in many other viral infections. Laboratory diagnosis is important when rubella is suspected in pregnant women or newborns. Consult infectious disease specialist (tests may include isolation of virus from nasopharynx or serology like rubella-specific IgM antibody and a fourfold rise or seroconversion between acute and convalescent IgG serum titers). Rubella infection is asymptomatic and requires no therapy in the majority of patients who recover without any sequelae. Patients with arthritis will require therapy directed at pain relief. Children with postnatal rubella should be excluded from schools and child care centers for 7 days after the onset of the rash.

Pearl

Rubella causes a 3-day discrete maculopapular rash associated with prominent tender enlargements of postauricular, suboccipital, and cervical lymph nodes.

Infectious Mononucleosis

Clinical Summary

Infectious mononucleosis (IM) is caused by Epstein-Barr virus (EBV) in >90% of cases. Five to 10% of IM-like illness is caused by cytomegalovirus, Toxoplasma gondii, adenovirus, viral hepatitis, and HIV. IM is named for mononuclear lymphocytosis with atypical lymphocytes that accompanies the illness. IM occurs in all age groups with variable clinical expression. In young children, it is often asymptomatic or indistinguishable from other infections. In adolescents and young adults, the presentation is more classic and is transmitted by oral secretions by close contact such as kissing (hence called “kissing disease”) or exchange of saliva from child to child (eg, child care centers). The period of communicability is indeterminate. The incubation period is 30 to 50 days. Patients present with fever, myalgias, headache, anorexia, chills, and sore throat with moderate to severe exudative tonsillopharyngitis associated with bilateral anterior and posterior cervical lymph adenopathy (nodes mildly tender to palpation); submandibular, axillary, inguinal, or epitrochlear nodes may also be involved. Other features include hepatic manifestations (transient elevations of liver enzymes [˜80% to 90%]), hepatomegaly (˜10% to 15%), splenomegaly (moderate enlargement in ˜50%), and skin rash (˜5% to 15% of cases), which can be morbilliform, scarlatiniform, macular, petechial, urticarial, or erythema multiforme–like. Complications include upper airway obstruction, splenic rupture, hematologic (eg, thrombocytopenia, hemolytic anemia), cardiac (eg, myocarditis), disseminated lymphoproliferative disease, and chronic fatigue syndrome. Differential diagnosis includes streptococcal pharyngitis, leukemia, other viral exanthems, viral hepatitis, and diphtheria.

Figure 3.58 ▪ Exudative Tonsillopharyngitis of Infectious Mononucleosis.

Marked white exudates on the tonsils of a child with IM. (Reproduced with permission from: Mei Kane KS, Ryder JB, Jonson RA, et al: Epstein-Barr virus. Color Atlas & Synopsis of Pediatric Dermatology. New York, McGraw-Hill, 2002, p. 576.)

Emergency Department Treatment and Disposition

Obtain CBC with peripheral smear, which will show leukocytosis with predominant lymphocytosis and atypical lymphocytes usually >10% (other viral infections usually <10%). Consider Monospot test (usually negative in children <4 years; heterophil antibody test identifies about 85% of cases of IM in older children during the second week of illness), and if required, EBV serology tests (eg, IgM and IgG antibodies to viral capsid antigen [VCA], antibody to early antigen [EA], and antibody to EBV nuclear antigen [EBNA]).

Figure 3.59 ▪ Infectious Mononucleosis.

Cervical lymphadenopathy and mouth breathing are noted in this child who presented with difficulty breathing, fever, and sore throat. His monospot was positive and had 25% atypical lymphocytes on the peripheral smear. (Photo contributor: Binita R. Shah, MD.)

Figure 3.60 ▪ Infectious Mononucleosis.

Cervical and submental lymphadenopathy (arrow) and mouth breathing are seen in this child who presented with “worsening of his snoring” sore throat, and fever. For upper airway obstruction due to IM see also Fig. 6.39. (Photo contributor: Binita R. Shah, MD.)

Figure 3.61 ▪ Ampicillin (or Other Penicillin) Related Rash in Infectious Mononucleosis.

(A) This generalized erythematous papular rash was precipitated by amoxicillin, which was given to this patient 5 days earlier for exudative tonsillopharyngitis (presumed to be “strep throat”). Fever continued while on amoxicillin. He also had splenomegaly and atypical lymphocytosis. Administration of ampicillin (or other penicillin) produces a rash in up to 90% to 100% of patients with IM. The rash may be pruritic, erythematous, or copper-colored maculopapular rash that begins 5 to 10 days after the drug is begun and lasts up to 1 week. Involvement can be extensive on trunk, including involvement of palms and soles. (B) Amoxicillin rash in a different patient with IM. This rash is not an allergic reaction to penicillin. True penicillin-allergic skin manifestations include urticaria, erythema multiforme, and Stevens-Johnson syndrome/toxic epidermal necrolysis. (Photo contributors: Binita R. Shah, MD [A] and Andrea Marmor, MD [B].)

IM is typically self-limited and patients recover without specific therapy. Admit patients with complications such as upper airway obstruction. Corticosteroid therapy is not routinely recommended; however consider a short course of prednisone given orally for 7 days with subsequent tapering if there is upper airway obstruction. Advise family/patient to avoid contact sports or heavy lifting until full recovery of splenomegaly and refer such patients to the primary care physician for monitoring. Educate family about signs of splenic rupture (eg, sudden-onset abdominal pain, especially left-sided; vomiting; pallor; lethargy; or fatigue [signs/symptoms of hemorrhage]).

Figure 3.62 ▪ Splenic Rupture; Infectious Mononucleosis.

CT scan of the abdomen demonstrates grade 4 laceration of the spleen, extending to hilum with smaller areas of laceration. Active extravasation was also noted on a different CT image. This 16-year old adolescent male presented with abdominal pain, left shoulder pain and feeling dizzy following trauma to his left side of the abdomen while wresting in the school. He had a syncopal episode while in the ED. He had sore throat 2 weeks prior to this. Splenic rupture is a rare but serious complication leading to hemorrhage, shock, and death. Incidence of rupture is highest in 2nd or 3rd week of illness. Rarely this may a first sign of IM as seen in this patient. (Photo/legend contributors: Vikas S. Shah, MD/John Amodio, MD.)

Pearls

Classic IM is an acute illness characterized by a triad of fever, exudative pharyngitis, and cervical adenopathy.
IM spectrum varies from asymptomatic infection to fatal infection; most frequent causes of mortality are neurologic complications, splenic rupture, or upper airway obstruction.
Streptococcal pharyngitis mimics IM; tender tonsillar and cervical adenopathy and absence of hepatosplenomegaly may help in differentiating between the two. Suspect IM when a patient with “strep throat” does not improve within 48 to 72 hours after antibiotics.
Ampicillin or amoxicillin given to patients with IM causes nonallergic morbilliform rash that is often mistaken for penicillin allergy.

Erythema Infectiosum

Clinical Summary

Erythema infectiosum (also known as fifth disease) is a exanthematous illness caused by human parvovirus B19. Sporadic cases are seen throughout the year, while seasonal peaks occur in late winter and spring, most commonly affecting school-aged children. The incubation period ranges from 4 to 21 days. The prodrome of myalgia and headache may be absent or mild; patients are usually afebrile (or low-grade fever) presenting with a rash. The disease occurs in three stages. First is a rash of red flushed cheeks with circumoral pallor (slapped-cheek appearance) lasting 1 to 4 days. This is followed by a symmetric, erythematous maculopapular rash beginning on the trunk and spreading to the arms, buttocks, and thighs. The palms and soles usually are spared and the rash is more prominent on extensor surfaces. The rash is often pruritic. As the rash clears spontaneously, there is central clearing, making the rash appear reticulated or lace-like. Desquamation does not occur and the rash resolves within 3 weeks. However, in the third stage of the disease, there is recurrent waxing and waning of rash (for weeks or sometimes months) precipitated by a variety of stimuli (eg, sunlight, vigorous exercise, hot shower, stress).

Figure 3.63 ▪ Slapped-Cheek Appearance of Erythema Infectiosum.

Slapped-cheek appearance in a child with parvovirus B19 infection. (Reproduced with permission from: Mei Kane KS, Ryder JB, Jonson RA, et al: Human parvovirus B19. Color Atlas & Synopsis of Pediatric Dermatology. New York, McGraw-Hill, 2002, p. 579.)

Complications include transient aplastic crisis in patients with hemolytic anemias (eg, sickle cell disease, thalassemia). Adolescent and young adults (more commonly females) may develop symmetrical peripheral polyarthropathy (hands, wrists, knees, ankles) that may last 2 to 4 weeks. Neurologic complications (eg, meningitis, encephalitis), thrombocytopenic purpura, and hydrops fetalis due to intrauterine infection of the fetus are other complications. Differential diagnosis includes other viral exanthems (eg, enteroviral infections), drug eruptions, and collagen vascular diseases (patients presenting with arthralgia/arthritis).

Emergency Department Treatment and Disposition

Diagnosis is clinical based on the exanthema and no laboratory tests are required for immunocompetent children. For patients with hemolytic anemias, obtain CBC with reticulocyte count. Presence of anti-B19 IgM antibody on a single serum specimen confirms acute or recent infection. IgG antibodies are detected a few days after IgM antibodies and persist for years. The disease is self-limited and only supportive therapy is required for immunocompetent patients. Children do not need isolation and exclusion from school or day care as they no longer are contagious once the rash appears. Educate family about possible recurrence of the rash. No specific therapy is necessary for arthritis except pain management. Admit patients with hemolytic anemias presenting with aplastic crisis for close monitoring and possible transfusion.

Figure 3.64 ▪ Erythema Infectiosum.

Lacy, reticulated rash on the body of a child with EI. (Reproduced with permission from: Shah BR, Laude TL: Erythema infectiosum. In: Atlas of Pediatric Clinical Diagnosis. Philadelphia, WB Saunders, 2000, p. 70.)

Pearl

Slapped-cheek appearance in an otherwise well-appearing child is pathognomonic of EI.

Figure 3.65 ▪ Papular Purpuric “Gloves and Socks” Syndrome in Parvovirus B19 Infection.

This syndrome is characterized by petechiae on the hands and feet that appear in a distinct gloves-and-socks distribution (with a clear line of distinction between rash and non-rash areas at wrists and ankles). It is usually seen in older children and adolescents with parvovirus B19 infection. (Photo contributor: Binita R. Shah, MD.)

Hand‐Foot‐and-Mouth Disease

Clinical Summary

Hand-foot-and-mouth disease (HFMD) is a clearly recognizable coxsackie or enterovirus infection commonly seen during late summer and early fall in temperate climates and often occurring in epidemics. HFMD is a highly contagious illness; modes of transmission include fecal-oral, respiratory route, and from fomites. The incubation period ranges from 4 to 7 days. Constitutional symptoms (eg, fever, diarrhea, anorexia) usually precede skin lesions. Location of lesions include hands/palms (dorsal and palmar surface, sides of fingers), feet (sides of feet and toes, plantar surface of soles), and mouth (anterior portion of mouth involving tongue and buccal mucosa, hard palate, gingivae, lips). Elliptical or oval gray-roofed vesicles with erythematous rims varying in size from 3 to 7 mm (up to 2 cm) and in number from a few to a hundred are seen. Skin lesions are bilateral and symmetric on hands and feet and usually are asymptomatic, whereas mouth lesions are painful. Nonvesicular papular, macular, or petechial lesions may be seen on the buttocks (most common site), upper thighs, and knees. Myocarditis, meningoencephalitis, and aseptic meningitis are rare complications. Differential diagnosis includes other viral exanthems with vesicular lesions (eg, varicella), herpes gingivostomatitis, herpangina, aphthous stomatitis, arthropod bites, and allergic contact dermatitis.

Figure 3.66 ▪ Hand‐Foot‐and-Mouth Disease.

Typical elliptical or oval-shaped papulovesicular lesions with erythematous rims are seen on the hand and foot (A) and (B), ulcers surrounded by a rim of erythema are seen in the mouth (C). A nonvesicular maculopapular rash (D) is also seen on the buttocks which is the most common site. Similar lesions may also be seen on the upper thighs and knees (arms, legs, and face are less commonly involved). (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is made clinically, and no laboratory tests are usually performed. Treatment is supportive with antipyretics/analgesics (as indicated) with attention to adequate hydration. Soft diet and cool, noncitrus liquids are often well tolerated in the presence of oral ulcerations. Advise regarding personal hygiene including hand washing to prevent spread of the infection. HFMD usually is a self-limited disease with lesions lasting 2 to 7 days and healing without scarring.

Pearls

HFMD is characterized by vesicular lesions in the mouth, hands, and feet. However, all three anatomic areas need not be affected. The mouth is most frequently involved, followed by hands than feet.
Do not use lidocaine viscous topically for pain relief in the mouth. Systemic toxicity can occur due to absorption of the lidocaine from the buccal mucosa.

Herpangina

Clinical Summary

Herpangina is a characteristic enanthem produced by enteroviruses like coxsackie A, coxsackie B, and echoviruses, affecting most commonly children between 3 and 10 years old. It is typically seen during summer or early fall in temperate climates. Constitutional symptoms (eg, fever, vomiting, sore throat, dysphagia) may be present. Discrete vesicles and/or ulcers (1–2 mm in diameter) surrounded by an erythematous ring occur on the anterior tonsillar pillars (most frequent site), soft palate, tonsils and uvula, and posterior pharyngeal wall. Number of lesions varies from a few to many, lasting for about 1 week. The course is benign in the majority of cases, without any complications. Differential diagnosis includes herpes simplex virus (HSV) gingivostomatitis and hand-foot-and-mouth disease.

Figure 3.67 ▪ Herpangina.

Typical yellowish-white ulcers or vesicles that measure usually about 1 to 2 mm in diameter surrounded by an erythematous base are seen. Typically in herpangina, these lesions are seen on the soft palate, tonsils, and uvula. Gingiva, tongue, and buccal mucosa are spared (unlike herpetic gingivostomatitis in which gingiva, tongue, and buccal mucosa are involved). (Reproduced with permission from: Greenberg MI (ed): Greenberg’s Text Atlas of Emergency Medicine. Lippincott Williams and Wilkins, Philadelphia, 2005, p. 156.)

Emergency Department Treatment and Disposition

Diagnosis is made clinically, and usually no laboratory tests are performed. Treatment is symptomatic, with attention to maintaining good hydration. Soft diet and cool, noncitrus liquids are often well tolerated in the presence of oral ulcerations.

Pearls

Herpangina causes tiny vesicles and ulcers on the posterior pharynx. HSV gingivostomatitis causes ulcers in the posterior and anterior oropharyngeal mucosa involving tongue, buccal mucosa, and gums which are swollen and may bleed with minor trauma.
Hand-foot-and-mouth disease causes oval-shaped vesicles with erythematous rims on hands, feet, and mouth associated with nonvesicular papular, macular, or petechial lesions that may be seen on buttocks, upper thighs, and knees.

Cutaneous Larvae Migrans

Clinical Summary

Cutaneous larvae migrans (CLM, also known as creeping eruption or sandworm disease) is a skin infestation caused most commonly by the larvae of the dog or cat hookworm (eg, Ancylostoma braziliense) and rarely by human nematodes (eg, Ancylostoma duodenale). A braziliense larvae infect dogs and cats by burrowing through the skin. Adult hookworms reside in the intestine and shed eggs in feces that are deposited on the ground. The eggs develop into infectious larvae outside the body in places protected from desiccation and temperature extremes, such as sandy, shady areas around beaches or under houses. The larvae penetrate human skin to initiate infection. CLM is commonly seen in people who come into contact with soil contaminated with cat and dog feces (eg, children, gardeners, sunbathers, playing in sandboxes, walking barefoot on a beach, and working in tight crawlspaces under houses). Larvae migrate through the skin (at the plane of the epidermal-dermal junction) and advance from several millimeters to a few centimeters a day, producing serpiginous tracks. Larval activity can continue for weeks to months; however, the organisms are unable to penetrate the basement membrane, and die within months because they cannot complete their life cycle in the human host. CLM occurs worldwide. Skin lesion begins as a stinging or tingling sensation and reddish papule at the site of larval penetration with an intense localized pruritus. A serpiginous, tortuous, slightly raised track (sometimes with vesicles and bullae) is seen in the upper epidermis; such tracks can grow 1 to 2 cm/day (larva typically located 1 to 2 cm in front of serpiginous eruption). New areas of involvement may appear every few days. Lesions may be single or numerous (if large areas of the body are exposed, eg, sunbathing). Systemic symptoms are absent. Common sites (any area may be affected) include foot, buttock, hand, and genitalia. Rare presentations include Löffler syndrome (pneumonitis with a large burden of parasites), myositis, and eosinophilic enteritis (larvae reaching the intestine). Peripheral eosinophilia may be present. Skin biopsy is not necessary for the diagnosis (eosinophilic inflammatory infiltrate without migrating parasite seen). Differential diagnosis includes tinea infections, contact dermatitis, granuloma annulare, and cutaneous pili migrans (embedded hair or creeping hair).

Figure 3.68 ▪ Cutaneous Larva Migrans.

Erythematous, intensely pruritic, tortuous, and serpiginous tracks of migrating larva in a 6-year-old patient with a history of walking barefoot on one of the Caribbean islands. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Diagnosis is clinical. CLM is usually a self-limited disease. Spontaneous cure occurs usually in several weeks to a few months even without treatment, as the larvae die. For symptomatic relief, prescribe oral albendazole or ivermectin.

Pearl

An advancing serpiginous growing tunnel in the skin associated with intense pruritus is pathognomonic of CLM.

Ascariasis

Clinical Summary

Ascariasis (roundworm) is a nematode infestation by Ascaris lumbricoides that occurs at all ages, most commonly in preschool- and early school–aged children. Adult worms live freely in the lumen of the small intestine (commonly in the jejunum and middle ileum) for up to a year, shedding eggs in the stool, leading to fecal-oral transmission. Low standards of hygiene, poor sanitation, and use of human feces as fertilizer are contributing factors. The majority of patients are asymptomatic. Pulmonary signs and symptoms occur as larvae migrate through the lungs and include fever, shortness of breath/dyspnea, substernal pain, wheezing/asthma, hemoptysis, rales, Löffler syndrome (transient pulmonary infiltrates), and peripheral eosinophilia. Gastrointestinal signs and symptoms caused by adult worms in the small intestine include abdominal pain (persistent or recurrent) and distension, vomiting (with or without bile), malabsorption, and diarrhea. Worms may be seen in vomitus or stools. Worm migrations at different sites may cause ascending cholangitis, acute pancreatitis, acute appendicitis, diverticulitis, gallstones (dead worms as nidus for stone), perforation, peritonitis, volvulus, intussusception and acute intestinal obstruction (seen in children with heavy infection). Stressful conditions (eg, fever, illness) stimulate adult worm migration. Allergic reactions (due to absorption of toxins from products of living or dead worms) include asthma, hay fever, and urticaria. Differential diagnosis of pulmonary ascariasis with eosinophilia includes asthma and Löffler syndrome from other parasites (eg, toxocariasis, strongyloidiasis, hookworm); differential of ascariasis-induced GI diseases include pancreatitis or appendicitis or cholecystitis from other etiologies.

Figure 3.69 ▪ Ascaris Lumbricoides.

This worm was vomited in the ED by a patient presenting with abdominal pain and several episodes of nonbilious vomiting. Roundworm is the largest intestinal nematode parasite of humans. Sites from which adult worms may be passed include the rectum, nose (after migration through the nares), and from the mouth in vomitus. Characteristic features of roundworms include tapered ends, length between 15 and 40 cm (females tend to be larger), and white or reddish-yellow in color. (Photo contributor: Binita R. Shah, MD.)

Emergency Department Treatment and Disposition

Identification of ova on direct smear of a fresh stool specimen or of adult worms in vomitus or feces (often brought to the ED by caretakers) confirms diagnosis. If infection is uncertain, examine direct smear of stool samples on three consecutive mornings. If biliary ascariasis is suspected, obtain ultrasound of the biliary tree. Prescribe orally albendazole as a single dose or mebendazole for 3 days. Consult surgery if patient presents with acute intestinal obstruction and admit for conservative management (eg, IV hydration, nasogastric suctioning), which may resolve symptoms. Surgical intervention may be still needed for obstruction or volvulus. In a patient with a mixed infestation, treat ascariasis first; treatment of other parasites first may stimulate a large worm burden to migrate simultaneously, causing obstruction.

Figure 3.70 ▪ Ascariasis.

Plain radiograph of the abdomen showing a curvilinear radiopaque density in the bowel lumen in the left iliac region (this radiopaque density represents a roundworm, as this patient gave a history of passing roundworms in the stool). He presented with clinical signs of intestinal obstruction. He responded to conservative management and passed several worms after receiving mebendazole therapy. (Photo contributor: Binita R. Shah, MD.)

Pearls

Ascariasis is the most prevalent human helminthic infestation.
Small diameter of the intestinal lumen and propensity to acquire large worm burdens predisposes children for acute intestinal obstruction.

Malaria

Clinical Summary

Malaria is a protozoan infection transmitted to humans by the bite of nocturnal-feeding Anopheles mosquitoes. Four species of Plasmodium that cause infection include P falciparum, P ovale, P vivax, and P malariae (most commonly P falciparum and P vivax). Less commonly, transmission occurs through transfusion, contaminated needles or syringes, or transplacentally. Malaria affects all ages, and infections can be acute or chronic. Though Anopheles mosquitoes are native to the United States, most cases here are imported. Following a 1- to 3-week incubation period in the liver, Plasmodium enters a 48- to 72-hour asexual erythrocyte cycle depending on the species. This explains the periodicity of high fever and shaking chills (febrile paroxysms) that are the classic presentation. Sweats, rigors, headache, and muscle aches are also seen. At first, the fever is irregular followed by paroxysms alternating with periods of fatigue in a cyclic pattern (as the infection becomes synchronized). Paroxysms coincide with rupture of schizonts. Nausea, vomiting, diarrhea, abdominal pain, arthralgia, and back pain may be present with paroxysms. Splenomegaly and hepatomegaly may occur and anemia/pallor, thrombocytopenia, leucopenia, leukocytosis, and jaundice may be present. Different species of Plasmodium cause specific symptoms.

Figure 3.71 ▪ Plasmodium Falciparum Malaria: Giemsa-Stained Thin Smear of Peripheral Blood.

(A) Multiple ring forms of P falciparum (arrow). Note that many of the RBCs are infected and some have two ring forms. Some of the rings have double chromatin dots. (B) Banana- or crescent-shaped gametocytes (arrow) of P falciparum. Note that the RBC membrane has been stretched to enclose the gametocyte. This child immigrated from Africa 2 weeks before his illness. (Photo contributor: Haseeb A. Siddiqi, PhD.)

Emergency Department Treatment and Disposition

Obtain CBC, comprehensive metabolic panel, a thick and thin peripheral smear (thick smear to detect organisms in erythrocytes, and thin smear to determine species). Obtain multiple smears per day and if possible at least one during or right after a fever spike. Consult infectious disease specialist and/or Centers for Disease Control (CDC) for treatment (http://www.cdc.gov/malaria/about/index.html). The percentage of erythrocytes harboring parasites and identification of species, both detected from a thin peripheral smear, help determine therapy. Admit any patient presenting with severe malaria with signs of CNS or other end-organ involvement, shock, metabolic abnormalities (eg, acidosis, hypoglycemia), or parasitemia >5% to the ICU for monitoring and therapy.

Table 3.4 ▪ Specific Symptoms Caused by Different Plasmodia