title: Paradoxical hypertrichosis and terminal hair change after intense pulsed light hair removal therapy.
abstract: BACKGROUND
  Although complications such as blister formation, erosion, and post-inflammatory hypo- and hyperpigmentation are well-known side effects of intense pulsed light (IPL) photoepilation, little is known about the paradoxical hypertrichosis after therapy.
  
  
  OBJECTIVE
  To report the paradoxically increased hair density and coarseness after IPL photoepilation.
  
  
  METHODS
  Within a period of 23 months, a total of 991 hirsute female patients were treated with IPL for photoepilation. The IPL system used was the Vasculight-SR, a multifunctional laser and IPL system (Lumenis Inc., Santa Clara, CA, USA). The cut-off filters frequently used were 695, 755 and 645 nm.
  
  
  RESULTS
  Paradoxical hypertrichosis and terminal hair change were detected after a few sessions of IPL therapy among 51 out of 991 patients. Our serial digital photographs, schematic diagrams, and hair counts before and after treatment confirmed the patients' claims. The other more commonly seen complications were epidermal burning with blisters, erosion, and crust formation followed by post-inflammatory hypo- and/or hyperpigmentation.
  
  
  CONCLUSIONS
  Paradoxical hypertrichosis and terminal hair change is a common complication of IPL photoepilation.
authors.affiliation: Department of Dermatology, Jondishapour University of Medical Sciences, Ahvaz, Iran. radmanesh_m@yahoo.com
authors.forename: Mohammad
authors.initials: M
authors.lastname: Radmanesh
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005145:Face; D005260:Female; D005500:Follow-Up Studies; D006204:Hair Removal / Q000009:adverse effects* / Q000379:methods*; D006628:Hirsutism / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D006983:Hypertrichosis / Q000209:etiology* / Q000503:physiopathology; D028022:Low-Level Light Therapy / Q000009:adverse effects* / Q000379:methods; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index