title: L-phenylalanine and UVA irradiation in the treatment of vitiligo.
abstract: In order to evaluate the efficacy of L-phenylalanine (L-Phe) in combination with UVA therapy for vitiligo an open trial (149 patients, 18 months) and a small double-blind trial (32 patients, 6 months) were conducted. Oral L-Phe loading resulted in peak plasma levels of L-Phe after 30-60 min and a slight increase in the plasma tyrosine level. Response to L-Phe plus UVA irradiation was positive, and various grades of repigmentation not exceeding 77% in the open and 60% in the blind trial were observed. An increased L-Phe dose resulted in increased L-Phe plasma levels but not in improved clinical results. The optimal L-Phe dose appears to be lower than 50 mg/kg/day. Although it is difficult to draw firm conclusions from the present investigation, we think that L-Phe may have a place in the treatment of vitiligo and its role merits further investigation.
authors.affiliation: Department of Dermatology, Academisch Medisch Centrum, University of Amsterdam, The Netherlands.
authors.forename: A H
authors.initials: AH
authors.lastname: Siddiqui
authors.forename: L M
authors.initials: LM
authors.lastname: Stolk
authors.forename: R
authors.initials: R
authors.lastname: Bhaggoe
authors.forename: R
authors.initials: R
authors.lastname: Hu
authors.forename: R B
authors.initials: RB
authors.lastname: Schutgens
authors.forename: W
authors.initials: W
authors.lastname: Westerhof
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006801:Humans; D008875:Middle Aged; D010649:Phenylalanine / Q000627:therapeutic use*; D014443:Tyrosine / Q000097:blood; D014467:Ultraviolet Therapy; D014820:Vitiligo / Q000097:blood / Q000628:therapy*
chemical_list: D014443:Tyrosine; D010649:Phenylalanine