Pityriasis rotunda in a Caucasian woman from the Mediterranean area.

Pityriasis rotunda (PR) has been known to affect, almost exclusively, Japanese and South African Bantu, often in association with various systemic diseases. However, the occurrence of PR in Caucasian patients is extremely rare, and has been previously described in only three reports. We hereby report a case of an apparently healthy Caucasian woman from Israel having clinical and histological features characteristic of PR. Pityriasis rotunda (PR) is a rare disorder of keratinization characterized by strikingly well demarcated, perfectly round scaly brownish patches of variable number and diameter located mainly on the trunk and extremities. The exact place of this disorder within the nosology of the cutaneous dermatoses is not yet fully established. However, most authors regard it as a special circumscribed form of acquired ichthyosis with a histological resemblance to ichthyosis vulgaris. For more than half a century following the first description of this disorder in 1906 cases reported were almost exclusively from the Far East, particularly from Japan, or in South African Negroids, with a few cases of West Indian Negroids, usually in association with various debilitating diseases. The first report of a Caucasian patient appeared in the literature in 1966 and since then there have been only two additional reports of PR in Caucasian patients.