title: The use of 0.25% zinc pyrithione spray does not enhance the efficacy of clobetasol propionate 0.05% foam in the treatment of psoriasis.
abstract: BACKGROUND
  It was discovered that Skin Cap (Cheminova Internacional S.A., Madrid, Spain), an over-the-counter psoriasis therapy with zinc pyrithione, contained clobetasol propionate and it was withdrawn from the market by the US Food and Drug Administration review. Some suggested that there might be a synergistic effect of zinc pyrithione with clobetasol propionate.
  
  
  OBJECTIVE
  We sought to evaluate the efficacy of clobetasol propionate 0.05% foam with and without the coadministration of a topical 0.25% zinc pyrithione spray in treating psoriasis involving sites other than the scalp.
  
  
  METHODS
  We conducted a randomized, double-blind, right/left study of patients with mild to moderate, generally symmetric, plaque-type psoriasis. Patients were assigned to treatment with clobetasol propionate foam on all psoriatic lesions and then randomly assigned to use zinc pyrithione spray to either the right or left side of their body (vehicle spray to be applied to the opposite side). There was a 2-week treatment phase (visits at baseline, week 1, and week 2) and a follow-up phase (visit at week 4), and all treatments were administered twice daily for 2 weeks. The primary outcome measure was the change from baseline to week 2 in the composite score of the signs of psoriasis (erythema, scaling, plaque thickness) for symmetric target lesions.
  
  
  RESULTS
  A total of 25 patients were enrolled; 24 completed the trial and 1 was lost to follow up. Of those who completed the study, 63% (15 of 24) were men, and the mean age (+/-SD) was 50 years (+/-12.2). After 2 weeks of therapy, the average decline in the composite score was 3.5 (+/-1.8) for monotherapy (clobetasol propionate foam and vehicle) and, similarly, 3.3 (+/-1.8) for clobetasol propionate foam plus zinc pyrithione spray (P =.5).
  
  
  CONCLUSIONS
  Zinc pyrithione spray does not appear to enhance the efficacy of clobetasol propionate foam after 2 weeks of therapy.
authors.affiliation: Department of Dermatology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
authors.forename: Tamara Salam
authors.initials: TS
authors.lastname: Housman
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Keil
authors.forename: Beverly G
authors.initials: BG
authors.lastname: Mellen
authors.forename: Martha A
authors.initials: MA
authors.lastname: McCarty
authors.forename: Alan B
authors.initials: AB
authors.lastname: Fleischer
authors.forename: Steven R
authors.initials: SR
authors.lastname: Feldman
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D002990:Clobetasol / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005938:Glucocorticoids; D006801:Humans; D008297:Male; D009942:Organometallic Compounds / Q000627:therapeutic use*; D011565:Psoriasis / Q000188:drug therapy*; D011725:Pyridines / Q000627:therapeutic use*; D016896:Treatment Outcome; D015032:Zinc / Q000627:therapeutic use*
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D009942:Organometallic Compounds; D011725:Pyridines; D002990:Clobetasol; D015032:Zinc; C010423:pyrithione zinc