title: Cryogen spray cooling and higher fluence pulsed dye laser treatment improve port-wine stain clearance while minimizing epidermal damage.
abstract: BACKGROUND
  When a cryogen spurt is applied to the skin surface for an appropriately short period of time (on the order of tens of milliseconds), the cooling remains localized in the epidermis, while leaving the temperature of the deeper port-wine stain (PWS) blood vessels unchanged.
  
  
  OBJECTIVE
  The objective of this study was to compare the efficacy and safety of noncooled laser treatment (NC-LT), and cryogen spray cooled laser treatment (CSC-LT) of PWS birthmarks in a large series of patients.
  
  
  METHODS
  A retrospective review was conducted of 196 patients with head or neck PWS birthmarks treated with the pulsed dye laser (lambda = 585 nm; taup = 450 microseconds) over a 7-year period. Subjects' ages ranged between 2 months and 62 years; there were 109 females and 87 males, all of whom were Asian. Ninety-eight patients received NC-LT using light dosages of 5-7 J/cm2. Subsequently, 98 patients received CSC-LT using light dosages of 8-10 J/cm2. The primary efficacy measure was the quantitative assessment of the blanching response scores of NC-LT PWSs as compared, on a blinded basis, to CSC-LT PWSs.
  
  
  RESULTS
  Based on chi-squared analysis, there were clinical, and statistically significant, differences in the blanching response scores favoring PWS receiving CSC-LT as compared to the NC-LT group (P <.001). Permanent scarring was noted in 3.1% (n = 3) of the patients in the NC-LT group. Permanent scarring was not observed in the CSC-LT treatment group. Transient hyperpigmentation was noted in 57% (n = 56) and 48% (n = 47) of the patients in the NC-LT and CSC-LT groups, respectively. In both groups, the transient hyperpigmentation resolved in all patients within 1 year. Two patients in the NC-LT group developed delayed permanent hypopigmentation. Permanent hypopigmentation was not observed in the CSC-LT group.
  
  
  CONCLUSIONS
  CSC permitted the use of higher incident light dosages leading to improved PWS clearance without producing complications such as permanent scarring or dyspigmentation.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: C J
authors.initials: CJ
authors.lastname: Chang
authors.forename: J S
authors.initials: JS
authors.lastname: Nelson
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003080:Cold Temperature; D005260:Female; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000008:administration & dosage*; D007223:Infant; D053685:Laser Therapy; D007834:Lasers / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D019339:Port-Wine Stain / Q000532:radiotherapy*; D012189:Retrospective Studies; D004980:Ethane / Q000031:analogs & derivatives; D005466:Fluorocarbons
chemical_list: D006845:Hydrocarbons, Fluorinated; C063006:norflurane; D004980:Ethane; D005466:Fluorocarbons