I don't know why people are saying B-19 is hand, foot and mouth disease IT"S NOT

fifth disease is what it is called;

"Although most persons with parvovirus B19 infection are asymptomatic or have mild, nonspecific, cold-like symptoms, several clinical conditions have been linked to the virus. Parvovirus B19 usually infects children and causes the classic “slapped-cheek” rash of erythema infectiosum (fifth disease). The virus is highly infectious and spreads mainly through respiratory droplets. By the time the rash appears, the virus is no longer infectious. The virus also may cause acute or persistent arthropathy and papular, purpuric eruptions on the hands and feet (“gloves and socks” syndrome) in adults. Parvovirus B19 infection can trigger an acute cessation of red blood cell production, causing transient aplastic crisis, chronic red cell aplasia, hydrops fetalis, or congenital anemia. This is even more likely in patients with illnesses that have already shortened the lifespan of erythrocytes (e.g., iron deficiency anemia, human immunodeficiency virus, sickle cell disease, thalassemia, spherocytosis). A clinical diagnosis can be made without laboratory confirmation if erythema infectiosum is present. "