Variations in the natural history of psoriasis.

Latent psoriasis is a state which exists before the development of clinical psoriasis and wherein probably some as yet undiscovered defect exists. Investigation concerning a group of persons with latent psoriasis might disclose basic aberrations. The natural course of psoriasis may be altered by therapy. Folic acid antagonists and intradermal corticosteroids may at times eclipse psoriatic lesions. Oral adrenal corticosteroids may prove morbidistatic but on discontinuance a rebound flare may occur which is both protracted and recalcitrant. Antimalarial agents when employed as therapy for coexistent arthridites may cause psoriasis to become more severe. The Goeckerman regimen which employs topical tar and ultraviolet light therapy produces in some 75 per cent of patients a prolonged remission. As it is safe and repeatable it is favored for the usual severe case of psoriasis. Psoriasis therapy is better assessed by considering its effect on the natural evolution of the disease.