title: The reservoir effect of topical steroids in vitiliginous skin: A cross-sectional study.
abstract: BACKGROUND
  Prolonged and frequent use of topical steroids may lead to decrease in efficacy as well as many local adverse effects. Stratum corneum has a unique property of reservoir effect.
  
  
  OBJECTIVE
  To study the reservoir effect of topical steroids in a steroid-responsive condition which may enable a decrease in the dosing frequency of topical steroids.
  
  
  METHODS
  A cross-sectional study design was used. Patients with at least three vitiliginous patches of more than 2 cm 2 present over the trunk or limbs were included. Exclusion criteria were topical or systemic corticosteroid use within the previous 4 weeks, antihistamine use within the previous 7 days, history of any allergy in the past and immunosuppression. Clobetasol propionate cream was applied on the first vitiliginous area (site A) and fluticasone propionate ointment was applied on the second vitiliginous area (site B). The third vitiliginous area, site C (control site) was left without applying any medication. Histamine-induced wheal suppression test was performed on each site, at the same time of the day, on every consecutive day following steroid application, until the values obtained at sites A and B approached those obtained at site C. SPSS software for Windows, version 16.0 was used for statistical analysis. The mean and standard deviation of the various studied parameters were calculated for various treatment groups and compared using analysis of variance (ANOVA) test.
  
  
  RESULTS
  Forty patients were included in the study. The average wheal volumes and average erythema sizes at sites A and B were significantly smaller than the corresponding values at site C for up to 5 days after applying medication (P < 0.001).
  
  
  CONCLUSIONS
  The presence of a cutaneous reservoir of topical steroid was confirmed based on its suppressive effect on the wheal and flare response to histamine. It is not certain that the concentration that suppresses histamine-induced wheal and flare is sufficient for therapeutic efficacy in vitiligo.
  
  
  CONCLUSIONS
  The reservoir effect of topical clobetasol propionate and fluticasone propionate persisted for 5 days in vitiliginous skin. Hence, it may be possible to reduce the frequency of topical steroid application in vitiligo.
authors.affiliation: Department of Dermatology and Venereology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Utter Pradesh, India.
authors.forename: Satyendra Kumar
authors.initials: SK
authors.lastname: Singh
authors.forename: Farzeen
authors.initials: F
authors.lastname: Nasir
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000378:metabolism*; D002990:Clobetasol / Q000008:administration & dosage / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D000068298:Fluticasone / Q000008:administration & dosage / Q000378:metabolism*; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009824:Ointments / Q000008:administration & dosage / Q000378:metabolism; D012867:Skin / Q000187:drug effects; D063465:Skin Cream / Q000008:administration & dosage / Q000378:metabolism; D013618:Tachyphylaxis; D014820:Vitiligo / Q000188:drug therapy* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D009824:Ointments; D006632:Histamine; D002990:Clobetasol; D000068298:Fluticasone