title: Treatment of nevus of Ota by the Q-switched alexandrite laser.
abstract: BACKGROUND
  The Q-switched alexandrite laser (755 nm, 100 nanoseconds) selectively targets and destroys cutaneous pigment such as that found in dermal pigmented lesions and tattoos. The nevus of Ota is a benign dermal melanocytic lesion, which, due to its large size and periocular location, has been notoriously difficult to treat. Utilizing the principles of selective photothermolysis, the alexandrite laser could effect an excellent treatment for nevus of Ota.
  
  
  OBJECTIVE
  To report the effectiveness of the Q-switched alexandrite laser in treating nevus of Ota.
  
  
  METHODS
  Seven patients with nevus of Ota were treated with the Q-switched alexandrite laser (755 nm, 100 nanoseconds) with energy densities ranging from 4.75 to 7.0 J/cm2 at 8-12-week intervals. Response to therapy was evaluated through independent observation and rating of sequential photographs by two blinded observers. Histologic examinations of lesional skin biopsies before and after completion of laser treatments were performed.
  
  
  RESULTS
  An average of two laser treatments were required to effect an average clinical improvement of 50%. Five patients showed 100% lesional clearance after an average of five treatments. No scarring, textural changes, or pigmentary side effects were observed in treated skin. Histology of laser-irradiated lesions revealed elimination of upper dermal pigmentation without epidermal disruption, and rare melanophages and pigmented spindle cells in the deep reticular dermis. No lesional recurrences were observed up to 1 year following treatment.
  
  
  CONCLUSIONS
  The Q-switched alexandrite laser can effectively eliminate nevus of Ota without untoward side effects, such as scarring.
authors.affiliation: Department of Dermatology, Georgetown Washington, DC, USA.
authors.forename: T S
authors.initials: TS
authors.lastname: Alster
authors.forename: C M
authors.initials: CM
authors.lastname: Williams
mesh_terms: D000293:Adolescent; D000328:Adult; D000537:Aluminum Oxide; D001608:Beryllium; D005153:Facial Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006644:Histiocytes / Q000473:pathology; D006801:Humans; D017075:Laser Coagulation / Q000295:instrumentation / Q000379:methods; D008297:Male; D008543:Melanins; D009507:Nevus of Ota / Q000473:pathology / Q000601:surgery*; D010587:Phagocytosis; D010781:Photography; D012074:Remission Induction; D012878:Skin Neoplasms / Q000473:pathology / Q000601:surgery*; D012880:Skin Pigmentation / Q000528:radiation effects
chemical_list: D008543:Melanins; D000537:Aluminum Oxide; D001608:Beryllium