title: Becker's naevus: a comparative study between erbium: YAG and Q-switched neodymium:YAG; clinical and histopathological findings.
abstract: BACKGROUND
  Becker's naevus (BN) may represent a distressing cosmetic handicap and a challenging issue regarding treatment.
  
  
  OBJECTIVE
  To compare clinical and histopathological findings of patients with BN treated with two different lasers: an erbium:yttrium-aluminium-garnet (Er:YAG) system vs. a neodymium:YAG (Nd:YAG) laser.
  
  
  METHODS
  In this prospective and comparative study we present the clinical and histopathological evolution during a 2-year follow-up of 22 patients with BN treated with only one pass of the Er:YAG laser (n = 11) or three treatment sessions with the Q-switched Nd:YAG system (n = 11).
  
  
  RESULTS
  Clinical evaluation 2 years after treatment with the Er:YAG laser showed complete clearance (100%) in 54% of the patients (n = 6) and clearance of > 50% in 100% of the subjects. In relation to Nd:YAG laser treatments our results echo those of other authors. Numerous sessions are necessary to get an acceptable clinical clearance rate. Only one patient showed marked clearance (51-99%) after three treatment sessions. Moderate (26-50%) and mild (1-25%) clearance was observed in 45.5% (n = 5) and 27.3% (n = 3) of the patients.
  
  
  CONCLUSIONS
  Both Er:YAG and Nd:YAG are safe tools to treat BN. However, in terms of pigment removal, one pass with Er:YAG is a superior technique to three treatment sessions with the Nd:YAG.
authors.affiliation: Instituto Médico Vilafortuny and Antoni de Gimbernat Foundation, Av. Vilafortuny 31, E-43850 Cambrils, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Trelles
authors.forename: I
authors.initials: I
authors.lastname: Allones
authors.forename: G A
authors.initials: GA
authors.lastname: Moreno-Arias
authors.forename: M
authors.initials: M
authors.lastname: Vélez
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017075:Laser Coagulation / Q000009:adverse effects / Q000379:methods*; D053685:Laser Therapy; D007834:Lasers / Q000009:adverse effects; D008297:Male; D009508:Nevus, Pigmented / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D016896:Treatment Outcome