Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Gray, adherent pseudomembrane, most often in the pharynx but also in the nasopharynx or trachea Sore throat, serosanguinous nasal discharge, hoarseness, and fever in a nonimmunized child Peripheral neuritis or myocarditis Positive culture Treatment should not be withheld pending culture results +++ General Considerations ++ Defined as an acute infection of the upper respiratory tract or skin caused by toxin-producing Corynebacterium diphtheriae In immunized communities, infection probably occurs through spread of the phage among carriers of susceptible C diphtheriae rather than through spread of phage-containing bacteria themselves Diphtheria toxin kills susceptible cells by irreversible inhibition of protein synthesis Toxin is absorbed into the mucous membranes and causes destruction of epithelium and a superficial inflammatory response Necrotic epithelium becomes embedded in exuded fibrin with WBCs and RBCs (red blood cells), forming a grayish pseudomembrane over the tonsils, pharynx, or larynx Incubation period is 2–7 days +++ Demographics ++ Disease is rare in the United States; five cases have been reported since 2000; none since 2003 However, significant numbers of elderly adults and unimmunized children are susceptible to infection Occurs in epidemics in countries where immunization is not universal Unimmunized travelers to these areas may acquire the disease +++ Clinical Findings +++ Symptoms and Signs ++ Pharyngeal diphtheria Early manifestations are mild sore throat, moderate fever, and malaise, followed fairly rapidly by prostration and circulatory collapse Pulse is more rapid than the fever would seem to justify A pharyngeal membrane forms May spread into the nasopharynx or the trachea, producing respiratory obstruction Tenacious and gray Surrounded by a narrow zone of erythema and a broader zone of edema The cervical lymph nodes become swollen, which is associated with brawny edema of the neck (so-called bull neck) Laryngeal diphtheria presents with stridor, which can progress to airway obstruction Cutaneous, vaginal, and wound diphtheria Account for up to one-third of cases Characterized by ulcerative lesions with membrane formation +++ Differential Diagnosis ++ Pharyngeal diphtheria resembles pharyngitis secondary to β-Hemolytic streptococcus Epstein-Barr virus Other viral respiratory pathogens A nasal foreign body or purulent sinusitis may mimic nasal diphtheria Other causes of laryngeal obstruction include epiglottitis and viral croup Guillain-Barré syndrome, poliomyelitis, or acute poisoning may mimic the neuropathy of diphtheria +++ Diagnosis ++ Clinical Direct smears are unreliable Cultures Material is obtained from the nose, throat, or skin lesions Specialized culture media are required Between 16 and 48 hours are required before identification of the organism May be negative in individuals who have received antibiotics A toxigenicity test is performed WBC count usually is normal Hemolytic anemia and thrombocytopenia are common +++ Treatment +++ General Measures ++ Obervation of patients in the hospital ... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth