Phototherapy and photochemotherapy.

This is a review of present knowledge of the use of ultraviolet (UV) radiation in the treatment of skin diseases. Two methods are currently used: phototherapy with UVB, and photochemotherapy with UVA and psoralens as photosensitizers. Both forms have their place in dermatologic therapy. In particular, photochemotherapy has become a standard treatment for severe psoriasis, mycosis fungoides, vitiligo, and some other dermatoses; it is effective as prophylactic treatment in polymorphic light eruption and other photodermatoses. This report will focus on indications, possible mechanisms, and treatment results. In addition, the potential acute and chronic side effects of these therapies are reviewed with special emphasis on skin carcinogenesis.