Psoriasis is an antidote for dermatologists' ego. It is the most vulnerable point in their armor as experts, and it remains the most baffling of dermatoses despite the great advances recently made in dermatology. Dermatologists of today can ill afford to look askance at the masters of yesterday, for except in diagnosis and palliative treatment they have accomplished nothing in the management of this disease.
Because of its antiquity, its confusion with leprosy and other dermatoses and the complete lack of progress both in its therapeutics and in the knowledge of its pathogenesis, the disease is of extraordinary interest, historically as well as philosophically. There is scarcely a therapeutic measure or an etiologic factor mentioned today which did not originate in the minds of dermatologists seventy or more years ago. It is passing strange that this apparent checkmate should have occurred in this particular disease. When one considers