title: Fractional photothermolysis laser treatment of male pattern hair loss.
abstract: BACKGROUND
  Various trials have been conducted on the management of male pattern hair loss (MPHL). A variety of laser and light sources have been used for the treatment of MPHL.
  
  
  OBJECTIVE
  To understand the effects of a 1,550-nm fractional erbium-glass laser on the hair cycle in an alopecia mouse model and to study the clinical effects of the same laser used as treatment for MPHL.
  
  
  METHODS
  Irradiation was applied to the shaved skin of C3H/HeN mice using various energy and density settings and varied irradiation intervals. In a clinical pilot study involving human subjects, 20 participants were treated over five sessions at 2-week intervals. A fractional photothermolysis laser was used at the energy of 5 mJ and a total density of 300 spots/cm(2).
  
  
  RESULTS
  In the animal study, the hair stimulation effects were dependent upon the energy level, density, and irradiation interval. The anagen conversion of hair and the increase in Wnt 5a, β-catenin signals were observed. In the human pilot study, incremental improvements in hair density and growth rate were observed.
  
  
  CONCLUSIONS
  This pilot study showed that a 1,550-nm fractional erbium-glass laser might induce hair growth, but more intensive studies are required to clarify the clinical applications of this treatment.
authors.affiliation: Department of Dermatology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won-Serk
authors.initials: WS
authors.lastname: Kim
authors.forename: Hye In
authors.initials: HI
authors.lastname: Lee
authors.forename: Jin Woong
authors.initials: JW
authors.lastname: Lee
authors.forename: Yun Young
authors.initials: YY
authors.lastname: Lim
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Beom Joon
authors.initials: BJ
authors.lastname: Kim
authors.forename: Myeung Nam
authors.initials: MN
authors.lastname: Kim
authors.forename: Kye Yong
authors.initials: KY
authors.lastname: Song
authors.forename: Won Serk
authors.initials: WS
authors.lastname: Park
mesh_terms: D000328:Adult; D000505:Alopecia / Q000628:therapy*; D000818:Animals; D019583:Dose Fractionation, Radiation; D004871:Erbium; D005898:Glass; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008875:Middle Aged; D010865:Pilot Projects; D056910:Republic of Korea; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome
chemical_list: D004871:Erbium