Although there are numerous reports of erythema infectiosum in the literature, it appears to be a disease that is not well known. It is probably not rarely encountered in practice, but it is unrecognized as such and thus mislabeled. The occasion for discussing the subject again is the observation of a rather large epidemic of the disease in an orphanage in the city of New York, in which 80 children were affected, with a total of 170 attacks. Judging from the literature, there had been no previous epidemic of this condition in the city, although it has been observed elsewhere in the state (Hamburg and Elmsford). Approximately fifty localized epidemics have been reported in the literature. However, there is no doubt that sporadic cases also occur. HISTORICAL SURVEY The disease was first described under the name "örtliche Rötheln" by Tschamer1in 1889, although he first observed the disease in