title: The incidence of leukotrichia in segmental vitiligo: implication of poor response to medical treatment.
abstract: BACKGROUND
  In vitiligo, the melanocyte of the hair follicle is one of the major sources for repigmentation. Segmental vitiligo seems to be often associated with white hairs. However, in the case of small vellus hairs, it is often difficult or impossible to detect hair color. Thus, the real incidence of leukotrichia in segmental vitiligo has not been known.
  
  
  METHODS
  In this study, we investigated the existence of white hairs in the lesional skin of 82 patients with segmental vitiligo. When it was difficult to detect hair color with the naked eye or a magnifier, a digital microscope with 30× magnification was used.
  
  
  RESULTS
  Interestingly, all 82 patients showed leukotrichia in segmental vitiligo independent of age and disease duration. Some patients had more than 90% white hairs in the lesional skin, and they showed poor response to medical treatment.
  
  
  CONCLUSIONS
  Based on our results, a very high percentage of patients with segmental vitiligo may be associated with leukotrichia. Many white hairs in segmental vitiligo may contribute to the lack of response with medical treatment. The examination of hair color with a digital microscope may be very useful for the prediction of treatment outcome and decision of treatment modalities.
authors.affiliation: Department of Dermatology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. dylee@skku.edu
authors.forename: Dong-Youn
authors.initials: DY
authors.lastname: Lee
authors.forename: Cho-Rok
authors.initials: CR
authors.lastname: Kim
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Park
authors.forename: Joo-Heung
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D046169:Dermoscopy; D005260:Female; D006200:Hair Color; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010789:Phototherapy / Q000706:statistics & numerical data*; D012880:Skin Pigmentation; D017211:Treatment Failure; D014820:Vitiligo / Q000453:epidemiology* / Q000601:surgery / Q000628:therapy*; D055815:Young Adult