Pityriasis amiantacea and psoriasis. A follow-up study.

59 patients with pityriasis amiantacea (PA) were followed up after 8 years on average. 15% had suffered from psoriasis and 19% were aware of psoriasis in their relatives. The incidence of psoriasis was significantly higher (p less than 0.01) than in the Scandinavian population, and the predisposition to psoriasis was significantly higher than in the population (p less than 0.001), but significantly lower (p less than 0.01) than in psoriatic patients. PA seems to be a manifestation of psoriasis in many cases.