[Observations on pityriasis rosea patients].

In the Institute of Skin and Veneral Diseases 252 patients suffering from pityriasis rosea were treated yearly since 1970. As opposed to descriptions published so far several differences were observed. The disease occurs not only in young adults, but also in infants and in old age. It may be observed not only in certain months, but throughout the year. The disease becomes manifest more frequently in workers of larger collectives. It does not leave behind prolonged immunity, but may return after an intervall of 1-12 years with milder symptoms. The repeated incidence was 3,57 per cent. Recurrence was observed in two cases within one family. P.r. was followed by herpes zoster in 3 cases, which is indicative of increased susceptibility for viral infection. The point of attack of the supposed pathogen is the pharyngeal mucous membrane, which may explain the difficulty of isolation of the unknown virus as this region has a rich microflora.