History:

Erythema infectiosum is caused by parvovirus B19.This condition has three phases.It begins abruptly with facial erythema known coloquially as the slapped cheeks syndrome.In the second stage a reticulate erythema occurs on the upper parts of the arms and legs and later on the buttocks.The trunk is relatively spared.The third phase is the recurring phase where the condition disappears only to reappear again in a few days,particularly after exposure to heat,sunlight or exercise.

This Dermatology Journal Online article gives an excellent account of the common viral exanthems.