Fourteen of 15 vitiligo patients responded to the topical use of methoxsalen and subsequent exposure to long-wave ultraviolet light. Three of the subjects showed complete repigmentation. Adverse reactions were prevented by using a controlled energy source with a light emission pattern corresponding to the biologic action spectrum of the photosensitizer. As a delayed 48 to 72 hour erythema was produced, only weekly treatments were necessary.
Repigmentation began after two to ten treatments and migrated out from the hair follicles or advanced in from the borders of the vitiliginous areas. This repigmentation was associated with the migration of Dopa-positive melanocytes into the treated areas.
Fulton JE, Leyden J, Papa C. Treatment of Vitiligo With Topical Methoxsalen and Blacklite. Arch Dermatol. 1969;100(2):224-229. doi:10.1001/archderm.1969.01610260100019