Fifth Disease (Erythema Infectiosum)

Diagnosis

Usually, your doctor can diagnose fifth disease by seeing the typical "slapped cheek" rash without fever or other signs of illness. Fifth disease rarely is diagnosed before the rash appears, since there may not be any early symptoms or they are mild and nonspecific. In rare cases, blood tests are done to look for specific antibodies against parvovirus B19. Antibodies are proteins made by the immune system to help protect the body against viruses or other invaders. The virus itself, or its viral DNA (genetic map), also can be detected in the blood of some patients.

Expected Duration

Fifth disease usually goes away within three weeks, but the rash may last longer. Although joint pains in adolescents may last for a few weeks or months, there are typically no long-term joint problems.