Most cases occur in school-age children. In adults, swelling of hands and feet along with arthritis are more common than in children. Fifty percent of women are susceptible to the B19 infection. Among pregnant women of unknown antibody protection status, fetal death after exposure to infection is estimated to be less than 1.5 percent. Risk to the fetus appears greatest if the infection occurs before the 20th week of pregnancy.
Transmission is, therefore, prevented through hand-washing and proper disposal of tissues used.
The incubation period is 4 - 14 days from the time of exposure to an infected person to the time the illness manifests itself. No treatment is needed except supportive care until there is a spontaneous recovery. Children can go back to school once the rash has appeared as they are no longer in the infectious stage of Fifth Disease. For expectant mothers, serologic testing as to their susceptibility is available, especially during community outbreaks. The Committee on Infectious Diseases states that outbreaks generally occurs in late winter and spring in elementary and junior high schools.