PITYRIASIS RUBRA PILARIS

Abstract

IT IS NOW generally agreed that some disturbance of vitamin A metabolism is important in the causation of pityriasis rubra pilaris.¹However, knowledge concerning the absorption, conversion, transport, storage, and utilization of this dietary factor is still far from complete, and very little is known of how or why this mechanism is interfered with in patients with pityriasis rubra pilaris. Two varieties of the disease may be distinguished: first, that in which there are definite indications of vitamin A deficiency, resulting from deficient intake, abnormal demand, or a gross fault in absorption, and which is readily improved by vitamin A therapy, and, second, that in which such gross deficiency cannot be demonstrated and which shows only slow response to ingestion of massive doses of the vitamin over a considerable time. In general, the first variety usually appears for the first time in adult life, while the latter