A 2-year-old boy presents with mild flu-like symptoms and a rash. He had erythematous malar rash and a "lace-like" erythematous rash on the trunk and extremities (Figures 133-1 and 133-2). The "slapped cheek" appearance made the diagnosis easy for fifth disease. The parents were reassured that this would go away on its own. The child returned to daycare the next day.
Classic erythematous malar rash with "slapped cheek" appearance of fifth disease (erythema infectiosum). (Reproduced with permission from Richard P. Usatine, MD.)
Classic fifth disease "lace-like" erythematous rash on the trunk and extremities. (Reproduced with permission from Richard P. Usatine, MD.)
Fifth disease is also commonly referred to as erythema infectiosum or slapped cheek syndrome. The name derives from the fact that it represents the fifth of the six common childhood viral exanthems described. Transmission occurs through respiratory secretions, possibly through fomites, and parenterally via vertical transmission from mother to fetus and by transfusion of blood or blood products.
Erythema infectiosum, parvovirus B19 infections, slapped cheek syndrome.
Fifth disease is common throughout the world, with antiparvovirus B19 immunoglobulin (Ig) G reported in approximately 50% to 70% of the United States, Asia, or Europe depending on the geographic location.1 The only known host for B19 is humans.2
Most individuals become infected during their school years, with the peak incident rates occurring in 6- to 14-year-old children and the age-specific risk being highest in children 7 to 9 years old.1,3
Fifth disease is very contagious via the respiratory route and occurs more frequently between late winter and early summer, specifically between December and July, with April accounting for 16% of infections.3 Up to 50% of the population is seropositive for antiparvovirus B19 IgG by age 18 years.3 In some communities, there are cycles of local epidemics every 4 to 7 years lasting up to 6 months at a time.1,4,5
Most cases of infection in pregnant women seem to occur in late spring and summer.6 Thirty percent to 40% of pregnant women lack measurable IgG to the infecting agent and are, therefore, presumed to be susceptible to infection.7 About 1% to 16% of susceptible pregnant women will develop serologic evidence in pregnancy.6,8 The risk of infection increases with increased exposure, such as working in nursery schools, after-school clubs, or daycare centers; having serious medical conditions; having stressful jobs; or having a first child or more than three children.6 Infection during pregnancy can in some cases lead to fetal death, although most fetuses ...