title: Histological hair removal study by ruby or alexandrite laser with comparative study on the effects of wavelength and fluence.
abstract: BACKGROUND
  Several different laser systems are currently used to remove unwanted hairs. In this study, we studied follicular changes following hair removal with ruby or alexandrite lasers at different fluences.
  
  
  METHODS
  Unwanted hairs were treated with a ruby laser (Chromos 694, ICN PhotonIcs, UK) at 10, 14 or 18 J/cm2 or with an alexandrite laser (LPIR, Cynosure, USA) at 11, 14 or 17 J/cm2. A 3 mm skin punch biopsy was taken immediately after each laser exposure and also 1 month later. Specimens were stained for histological observation. They were observed using immunohistochemistry with antibodies recognizing factor VIII related antigen or PCNA, and also by the TUNEL method. Similarly, electron microscopic observation was examined.
  
  
  RESULTS
  Immediately after the laser exposure, moderate follicular damage was observed following treatment with either type of laser. One month later, cystic formation of hair follicles and foreign body giant cells were observed in skin treated with either type of laser. A similar fluence with either laser treatment resulted in similar histological changes.
  
  
  CONCLUSIONS
  In this study, the histological changes following treatment with a ruby or an alexandrite laser at the same fluence are similar.
authors.affiliation: Department of Dermatology, Nippon Medical School, Tokyo, Japan.
authors.forename: Tokue
authors.initials: T
authors.lastname: Kato
authors.forename: Tokuya
authors.initials: T
authors.lastname: Omi
authors.forename: Zenya
authors.initials: Z
authors.lastname: Naito
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirai
authors.forename: Seiji
authors.initials: S
authors.lastname: Kawana
mesh_terms: D000328:Adult; D001608:Beryllium; D006197:Hair / Q000473:pathology* / Q000648:ultrastructure; D006204:Hair Removal; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000295:instrumentation; D053685:Laser Therapy; D007834:Lasers / Q000145:classification*; D008875:Middle Aged; D018809:Proliferating Cell Nuclear Antigen / Q000648:ultrastructure
chemical_list: D018809:Proliferating Cell Nuclear Antigen; C112654:alexandrite; D001608:Beryllium