title: Linear lichen planopilaris of the trunk: first report of a case.
abstract: BACKGROUND
  Lichen planopilaris (LPP) is believed to be a follicular variant of lichen planus that affects pilosebaceous units, mainly of the scalp. An extremely rare variant of LPP is a linear form, which follows the lines of Blaschko. Of the five previously documented cases of linear LPP, all were limited to the face.
  
  
  OBJECTIVE
  We report the case of a 34-year-old male who presented with a nonpruritic eruption on the trunk consisting of erythematous, keratotic, folliculocentric papules following Blaschko's lines.
  
  
  RESULTS
  Biopsy revealed lichenoid and interface dermatitis involving the basilar epidermis and hair follicles, as well as apoptotic keratinocytes, consistent with LPP.
  
  
  CONCLUSIONS
  This represents the first documented case of LPP, following the Blaschko's lines, in a nonfacial distribution.
authors.affiliation: Department of Pathology, Division of Dermatology, SMBD-Jewish General Hospital, McGill University, Montreal, QC.
authors.forename: Kristi
authors.initials: K
authors.lastname: Baker
authors.forename: Kevin
authors.initials: K
authors.lastname: Pehr
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D003937:Diagnosis, Differential; D006801:Humans; D006854:Hydrocortisone / Q000627:therapeutic use; D008010:Lichen Planus / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D013909:Thorax / Q000473:pathology*
chemical_list: D000893:Anti-Inflammatory Agents; D006854:Hydrocortisone