Determination of optimal topical photochemotherapy for vitiligo.

The efficacy of topical 8-methoxypsoralen (8-MOP) in varying concentrations and vehicles was assessed in 73 vitiligo patients. The response rates in different anatomic sites were also assessed. Seven patients (9%) had 100% repigmentation; 26 (36%) had 50% or greater repigmentation, 29 (40%) had some degree of pigment return, but less than 50%; 11 (15%) had no repigmentation. Results suggest that neither concentration of drug nor vehicle is a crucial factor for inducing repigmentation of vitiliginous patches on the face, trunk, and extremities. Low-dose 8-MOP (0.1%) was as effective as high dose 8-MOP (0.5%, 1%), while causing fewer side effects. However, when treating recalcitrant areas (distal extremities), 1% 8-MOP may be the most efficacious preparation for topical photochemotherapy. A phototoxic response preceded repigmentation in all cases. The following responses were obtained for the various anatomic sites treated: 56% of facial lesions; 35% of trunk areas; 36% of the extremities, and 13% of the recalcitrant areas had greater than 50% repigmentation.