Little has been added to the knowledge of pityriasis rubra pilaris since the original description of the disease and the nosologic controversy which it stimulated.1 The cause is unknown. Essentially a chronic, benign process in the skin, the disease runs a varied course and may show a familial trend. The review by Zeisler2 on this subject in 1923 is the last pertinent reference in the American literature. From time to time patients with pityriasis rubra pilaris are shown at various dermatologic meetings, but no more than 3 or 4 are shown a year, and these somewhat apologetically unless there is aroused some question of diagnosis or there is some feature of unusual interest, such as an early age of onset, an antecedent infection, a familial trend or a problem in treatment. The clinical appearance of patients with this disease is pathognomonic. The condition may be limited to certain