Toxic doses of vitamin A for pityriasis rubra pilaris.

Seven patients who were disabled by pityriasis rubra pilaris were given toxic doses of oral vitamin A (1 million IU/day in six of the seven patients) for five to 14 days. Within 72 hours, the patients began to exfoliate the hyperkeratotic and keratodermatous lesions. The desquamative process was completed between ten and 14 days. The skin remained erythematous for several months before assuming a normal color. The skin of six of the seven patients was virtually cleared by the treatment, and none suffered a relapse of the pityriasis rubra pilaris. Serial skin biopsy specimens showed evidence suggestive of an accelerated turnover rate of epidermal cells during treatment. Transient abnormalities of liver function test results were noted in two patients.