The rash can fade or become more intense when affected by exposure to sunlight and extreme temperature. The rash may last up to 20 days. It is important to note that by the time this rash appears, the disease in no longer infectious. The infectious period begins before onset of the rash. Some children may have brief non-specific symptoms like fever, malaise, muscle ache, sore throat, or headache followed a week later by the typical rash.
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.