title: Prospective study of pulsed dye laser in conjunction with cryogen spray cooling for treatment of port wine stains in Chinese patients.
abstract: BACKGROUND
  Pulsed dye laser (PDL) in conjunction with cryogen spray cooling (CSC) is effective in improving efficacy and safety for treatment of port wine stains (PWSs) in whites. However, for dark-skinned patients such as Chinese, only retrospective studies have been performed.
  
  
  OBJECTIVE
  To compare prospectively clinical efficacy in terms of blanching and acute and long-term adverse effects of PDL alone and PDL-CSC for treatment of PWSs in Chinese patients.
  
  
  METHODS
  Thirty-five Chinese patients (13 males and 22 females) were recruited, and 131 treatments were performed. Half of the test area on the PWS was treated with PDL alone, and the contralateral half was treated with PDL-CSC. The degree of PWS blanching was objectively assessed by spectrophotometer. Skin textural changes were detected by cutometer. All measurements were taken at baseline and before each subsequent laser treatment. Patients were interviewed immediately after treatment and again the following week using a visual analog scale questionnaire to assess the degree of pain and swelling. Occurrence of blisters was noted during each follow-up visit. Patients were evaluated for evidence of long-term adverse effects such as dyspigmentation and scarring after three treatments.
  
  
  RESULTS
  Statistically significant higher fluences were used on the PDL-CSC-treated group. The percentage change in the spectrophotometer a* value was significantly greater using PDL-CSC, indicating that there was more PWS blanching after treatment. There was no significant difference in the incidence of skin textural changes after three treatments with PDL alone or PDL-CSC. The immediate pain scores were significantly higher for PDL alone than with PDL-CSC. Blisters were significantly more common on the area treated using PDL alone than PDL-CSC. The overall incidence of long-term adverse effects was not significantly different between the PDL alone and PDL-CSC treatments. PDL-CSC was also the preferred treatment modality for most patients.
  
  
  CONCLUSIONS
  PDL-CSC was more effective than PDL alone for blanching of PWS in Chinese patients. Moreover, PDL-CSC was better tolerated and resulted in a lower incidence of acute adverse effects such as blistering.
authors.affiliation: Department of Medicine, Division of Dermatology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong, ROC.
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Chiu
authors.forename: Henry Hin-Lee
authors.initials: HH
authors.lastname: Chan
authors.forename: Wai-Sun
authors.initials: WS
authors.lastname: Ho
authors.forename: Chi-Keung
authors.initials: CK
authors.lastname: Yeung
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Nelson
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D002648:Child; D002675:Child, Preschool; D017679:Cryotherapy / Q000379:methods*; D005260:Female; D005466:Fluorocarbons / Q000627:therapeutic use; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019339:Port-Wine Stain / Q000208:ethnology / Q000628:therapy*; D011446:Prospective Studies; D012880:Skin Pigmentation
chemical_list: D005466:Fluorocarbons; C015531:tetrafluoroethylene