Fetal transmission may result in severe anemia with resultant congestive heart failure and fetal hydrops. There is no evidence of specific congenital malformations due to in-utero exposure to HPV B19. The exact role of HPV B19, if any, in these diseases is unclear. Peak incidence occurs in winter and early spring. Community epidemics usually last 3-6 months.
Subclinical infections are common.
Infants and adults are affected infrequently. EI is usually a biphasic illness. Mild prodromal symptoms begin approximately 1 week postexposure and last 2-3 days. Initially, a bright red, raised, slapped-cheek rash with circumoral pallor develops. The nasolabial folds are usually spared.