Recent advances in phototherapy and photochemotherapy of skin disease.

The therapeutic spectrum for ultraviolet radiation treatment of skin disease has continued to be broadened. Psoralen photochemotherapy is beneficial in chronic lichenoid graft-versus-host disease and disseminated granuloma annulare. This treatment is now being found more useful in atopic eczema and chronic photosensitivity with some modifications of the therapy. UV phototherapy has also been found useful in mild to moderate atopic eczema. The nature of these treatments is also changing with greater use of selective UV phototherapy and definition of the required schedule for maintenance treatment with UVB phototherapy. The mechanism of therapeutic benefit remains unknown although one possibility is selective phototoxicity for inflammatory cells in the dermis. Nonmelanoma skin cancer, premature aging of the skin and freckling are the main long-term adverse effects of these treatments.