title: Clinical and Histopathologic Assessment of Facial Melasma After Low-Fluence Q-Switched Neodymium-Doped Yttrium Aluminium Garnet Laser.
abstract: BACKGROUND
  Melasma is a frequent and difficult to treat skin disorder. Results of laser therapy are inconsistent.
  
  
  OBJECTIVE
  To determine the safety and efficacy of low-fluence Q-switched neodymium-doped yttrium aluminum garnet (QS Nd:YAG) laser for melasma treatment and assess recurrence rates and histopathologic findings before and after treatment.
  
  
  METHODS
  Twenty patients were treated with 10 weekly sessions of low-fluence 1064-nm QS Nd:YAG laser at 1-week intervals. The modified Melasma Area and Severity Index (mMASI) score was evaluated at baseline; 1 week; and 1, 3, and 6 months after treatment. Epidermal melanin quantification was performed on 10 biopsy samples and compared before and after treatment.
  
  
  RESULTS
  All patients showed improvement by mMASI scores, range (21%-75%) compared with that at baseline. No permanent side effects occurred. The recurrence rate was 81%. By histopathology, a slight, nonsignificant (p = .305) decrease in melanin deposition was seen in all layers of the epidermis 1 week after the laser treatments ended.
  
  
  CONCLUSIONS
  The results confirm the safety and effectiveness of low-fluence QS Nd:YAG laser for treating melasma; however, the high recurrence suggests poor long-term results when the laser is used as a monotherapy.
authors.affiliation: Department of Dermatology, Hospital das Clínicas da Universidade de São Paulo (HCFMUSP), Sao Paulo, Brazil.
authors.forename: Camila Anna
authors.initials: CA
authors.lastname: Hofbauer Parra
authors.forename: Mariana Figueroa
authors.initials: MF
authors.lastname: Careta
authors.forename: Neusa Yuriko Sakai
authors.initials: NY
authors.lastname: Valente
authors.forename: Nuno Eduardo Guimaraes
authors.initials: NE
authors.lastname: de Sanches Osório
authors.forename: Luis Antonio Ribeiro
authors.initials: LA
authors.lastname: Torezan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005148:Facial Dermatoses / Q000601:surgery*; D005260:Female; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008548:Melanosis / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies; D055815:Young Adult