Fever, a common presenting complaint in the acute care setting, may be associated with rash. The disorders that present with fever and rash range from benign and self-limited to rapidly progressive and life threatening. The entire clinical picture must be considered in a child presenting with fever and rash to facilitate timely diagnosis and treatment.
Skin lesions can be characterized by their morphology, color, distribution, and pattern. Based on this characterization, rash can be considered in six major categories:
Petechiae and purpura
The character of the rash combined with other signs and symptoms often suggests a specific cause of the illness.
A morbilliform rash appears as a generalized erythematous to pink maculopapular rash that blanches with pressure. Measles and rubella are classic infections (Table 97-1) representing this category. While widespread vaccination makes these diagnoses less likely, recent clusters of cases, particularly in unimmunized communities, should prompt consideration of these infections. Among immunized pediatric patients with morbilliform rash, a specific cause is identified in 37% to 48% of cases.1,2 Common culprits include parvovirus, human herpesvirus 6, enteroviruses, and group A Streptococcus. Other patients likely have unspecified self-limited viral infections, although drug eruption and Kawasaki disease should be considered in the differential diagnosis. Fever, rhinorrhea, and cough typically occur with these illnesses.
TABLE 97-1Key Features of Classic Childhood Exanthems ||Download (.pdf) TABLE 97-1 Key Features of Classic Childhood Exanthems
|Disease ||Cause ||Rash ||Clinical Findings ||Complications |
|Measles ||Measles virus ||Morbilliform rash, spreads from head to feet ||Koplik spots, fever, cough, coryza, conjunctivitis ||Bronchopneumonia, encephalitis, otitis media, myocarditis, encephalomyelitis, subacute sclerosing panencephalitis |
|Rubella (German measles) ||Rubella virus ||Discrete papular rash, spreads from head to feet ||Exanthema, rhinorrhea, tender adenopathy (postauricular, posterior cervical, postoccipital), low-grade fever ||Congenital rubella syndrome, arthritis, neuritis, encephalitis |
|Chickenpox ||Varicella virus ||Generalized, vesicular rash; “dewdrops on a rose petal” ||Fever, malaise, myalgias, pruritus ||Bacterial skin infection, pneumonia, hepatitis, encephalitis, cerebellar ataxia, other postinfectious neurologic syndromes |
|Erythema infectiosum (Fifth disease) ||Parvovirus B19 ||Erythematous, lacy, reticular rash on trunk and extremities; “slapped cheek” appearance ||Mild symptoms: headache, coryza, myalgia, arthralgia ||Aplastic crisis in patients with chronic hemolysis, chronic anemia in those with immunodeficiency, arthritis |
|Exanthema subitum (Roseola) ||Human herpesvirus 6 ||Centrally located, pink macular rash; onset as fever dissipates ||Often asymptomatic; fever, mild rhinorrhea occasionally ||Febrile seizures |
|Scarlet fever ||Streptococcus pyogenes (group A Streptococcus) ||Tiny, papular “sandpaper” rash; predilection for skin folds ||Exudative pharyngitis, fever, “strawberry” tongue, late desquamation ||Postinfectious sequelae (rheumatic fever, glomerulonephritis) |
The causes of vesiculobullous rash and fever are better defined. A generalized pattern of vesicles on an erythematous base (“dewdrops on a rose petal”) in various stages of eruption is characteristic of varicella, commonly called chickenpox. A dermatomal distribution suggests herpes zoster, particularly in patients with a history of varicella infection or vaccination. ...