Rubella (German measles). Rubella has a milder prodrome than measles; this typically consists of low-grade fever and anorexia. The rash is not as intense, but it usually follows the same pattern (first the face and neck, then the rest of the body; not palms or soles). Generally, the rash fades in the same sequence; however, it can resolve all at once.
Congenital rubella syndrome can cause deafness, eye defects (cataracts), and heart defects primarily in infants born to women who had primary infection in the first trimester.8 In addition, it has been associated with other abnormalities, including duodenal stenosis.9 The prevalence of rubella has decreased dramatically with the vaccination programs in developed countries but remains high in third world countries.
Figure 1 – The generalized maculopapular rash of erythema infectiosum develops on the neck, trunk, and extremities (A). As the rash fades, it has a lacy, reticular pattern (lesions on day 2, B). |  |
Erythema infectiosum. Popularly referred to as "fifth disease" (a reference to the old nomenclature that identified pediatric exanthemas by number), erythema infectiosum is caused by parvovirus B19. The only known hosts for the virus are humans. Erythema infectiosum is most commonly a disease of children aged 5 to 15 years, but it can occur at any age.
Patients are most contagious during the mild prodromal phase, which lasts for 2 to 5 days and consists of low-grade fever, headache, and malaise. Prodromal symptoms may also include arthralgia, arthritis, pharyngitis, conjunctivitis, cough, and diarrhea. The child is no longer contagious once the rash appears.10
This variable prodrome is followed by brilliant red patches on the cheeks, referred to as the "slapped cheek" sign. The erythema fades within hours to a few days, after which a generalized maculopapular rash on the neck, body, and extremities develops. As the rash resolves, it has a lacy, reticular pattern (Figure 1 A and B). The rash is more prominent with increased skin perfusion, such as occurs in a warm environment, with sunlight exposure, with feeding, or with exertion. When the patient is in a cooler environment or at rest, the rash appears to fade. The rash can wax and wane for weeks to months; however, it usually lasts 1 to 2 weeks. Rarely, the rash may be mildly pruritic or may be petechial.11
The appearance of the characteristic rash makes the diagnosis clear. In addition, once the rash has appeared, the patient is no longer contagious and the earlier symptoms have usually resolved fully.
Although a benign disorder in most children, erythema infectiosum can cause a significant aplastic crisis in patients with hemoglobinopathies (ie, sickle cell anemia), hemolytic anemia, or immunodeficiency. The infection can also cause fetal hydrops in susceptible pregnant women.
There is no specific antiviral therapy for erythema infectiosum. The symptoms of the prodrome are usually treated with acetaminophen or ibuprofen to relieve fever and discomfort.
Herpangina. This Enterovirus infection is usually caused by a coxsackievirus. Herpangina presents with low-grade fever, malaise, anorexia, and shallow vesicles or ulcerations of the posterior pharynx (including the uvula, soft palate, and tonsillar pillar). Like most enteroviral illnesses, herpangina tends to occur during the spring and fall.
Home therapy includes antipyretics and adequate fluid intake.12
Hand-foot-and-mouth disease. Like herpangina, this disease usually results from coxsackievirus infection. It begins with low-grade fever, malaise, anorexia, and posterior pharyngeal ulcerations. The oral lesions may involve the entire palate and tongue; the gingival mucosa is spared. Maculopapular lesions subsequently appear on the hands and feet (Figure 2); these progress to vesicles and then ulcerations.
Hand-foot-and-mouth disease is usually benign. However, many other enteroviruses can cause outbreaks of disease with similar features. One in particular, enterovirus 71 infection, has been associated with serious pulmonary and CNS complications.13 The identification of serological markers of hand-foot-and-mouth disease may be needed during an outbreak of enterovirus 71 infection. Therapy is usually the same as that for herpangina.
Figure 2 – These maculopapular lesions are characteristic of hand-footand-mouth disease. The rash appears on the hands and feet after a prodrome of low-grade fever, malaise, anorexia, and posterior pharyngeal ulcerations.
Roseola. Occasionally children present who recently had a high fever but now feel better—yet who have a new rash. This presentation is typical of roseola, a syndrome characterized by several days of high, unremitting fever followed by defervescence with the abrupt onset of a diffuse macular or maculopapular rash. Generally the child's clinical condition greatly improves with the onset of the rash.
Roseola is caused by herpesvirus 6 and rarely by herpesvirus 7. It typically occurs in children between 6 and 15 months of age. Infection with herpesvirus 6 can also present similarly to rubella and rubeola.
Patients with roseola often experience febrile seizures. Herpesvirus 6 can cause encephalitis as well.14 No therapies have been proven to prevent these febrile seizures, nor is any specific antiviral therapy available for roseola. Symptomatic therapy with antipyretics (other than aspirin), maintenance of good hydration, and reassurance are helpful.
