Chronic cutaneous effects of long-term psoralen and ultraviolet radiation therapy in patients with vitiligo.

Vitiligo is refractory to most therapeutic modalities. To assess the efficacy of a variety of PUVA therapies, we enrolled 596 subjects in a prospective study, and 230 were followed for up to 55 months. Various psoralen derivatives and dosage schedules were used. Each subject was examined at yearly intervals for therapeutic response and evidence of chronic PUVA toxicity. At 4 years after therapeutic inception, 29 (13%) developed lesions in remaining vitiliginous macules. Clinically, hyperkeratotic macules and hyperkeratotic, lichenoid, and telangiectatic papules were discerned. Histologic examination of these lesions revealed them to be actinic and lichenoid keratoses, verruca vulgaris, and hyperkeratosis with either hyperplasia or atrophy. No tumors were present. In perilesional skin, dermal collagen and elastic tissue degeneration, much greater in degree than reported in psoriatic skin, was observed. In this group of PUVA-treated patients, no increased risk of carcinoma was apparent during the follow-up period.