Fathoming Fifth Disease
Fifth disease is a mild viral illness that is common in children. It is caused by infection with the human parvovirus B19. The name fifth disease reflects the historical belief that it was one of the five diseases that produced a rash in children.
Fifth disease is also called erythema infectiosum. Erythema (redness) refers to the characteristic "slapped cheek" red rash on the face. This rash may itch. There may also be a lacy red rash on the trunk, arms, and legs. Before there is any rash, the child may have a low-grade fever and symptoms of a cold for several days. The rash itself goes away in seven to 10 days.
The causative virus, parvovirus B19, is thought to be transmitted from person to person via secretions from the mouth or nose. Sharing contaminated drinking cups or toothbrushes may transmit the virus. Unlike some other illnesses with rash, the contagious period in fifth disease is the time before the rash appears, when the child appears to just have a cold or a mild, nonspecific illness.
Fifth disease is very contagious. The CDC (U.S. Centers for Disease Control and Prevention) states that during an outbreak of fifth disease in a school, up to 60% of exposed children can contract the disease.