Photochemotherapy for psoriasis.

Photochemotherapy for psoriasis combining orally administered methoxsalen and long-wave ultraviolet (UVA) light was used in 186 patients with severe psoriasis. Several different phototherapy units with various numbers of GE high-output black lights were used. Excellent (90% to 100% clear) and good (80% to 90% clear) results were obtained in 77% of the patients. The average UVA dose at clearing was between 7 and 8 joules/sq cm. The majority of patients required one weekly maintenance UVA dose of their last clearing dose (joules per square centimeter) to remain clear. Side effects and abnormal laboratory findings were minimal.