title: Risk assessment of side effects from copper vapor and argon laser treatment: the importance of skin pigmentation.
abstract: OBJECTIVE
  Epidermal melanin is a limiting factor for obtaining beneficial results in dermatological treatment of vascular malformations. The aim of our study was to predict the highest laser intensity and energy fluence which can be applied to skin with different degrees of pigmentation before side effects are induced.
  
  
  METHODS
  Thirteen human volunteers with different degrees of skin pigmentation were laser-treated on the inside of the brachium with an argon laser (AL, 488 nm and 514.5 nm) and a copper vapor laser (CVL, 578 nm), both connected to a Hexascan. Three input intensities were used. 0.7, 1.0, and 1.3 W. Pulse duration was kept constant at 200 msec, resulting in hexascan fluences of 14.1, 20.2, and 26.2 J/cm2. At the 6-month assessment it was noted whether pigmentary changes or scarring were clinically absent or present. The results were analysed by logistic regression.
  
  
  RESULTS
  We found that pretreatment pigmentation percentage and laser intensity were significant risk factors of inducing side effects (P < .001), whereas it was without significant importance whether the AL or the CVL was used (P > .05). Contour lines of 1, 2.5, 5, 10, 25, and 50% risk levels of inducing clinically recognizable pigmentary changes and scarring were calculated. Pigmentary changes occurred at a significantly lower intensity level than skin texture changes (P = .006).
  
  
  CONCLUSIONS
  On basis of our results, we recommend assessment of skin pigmentation prior to laser treatment with the CVL and the AL, and we recommend that the illustrated risk levels are taken into consideration.
authors.affiliation: Department of Dermatology, Copenhagen University Hospital, Bispebjerg Hospital, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Haedersdal
authors.forename: H C
authors.initials: HC
authors.lastname: Wulf
mesh_terms: D000328:Adult; D001128:Argon; D002921:Cicatrix / Q000209:etiology / Q000473:pathology; D003300:Copper; D005260:Female; D006801:Humans; D007834:Lasers / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors; D012880:Skin Pigmentation / Q000528:radiation effects*
chemical_list: D001128:Argon; D003300:Copper