title: The use of pulsed dye laser for the prevention and treatment of hypertrophic scars in chinese persons.
abstract: BACKGROUND
  Pulse dye laser has been used with variable degrees of success in the treatment of hypertrophic scars, and although earlier reports suggested a significant degree of improvement, more recent studies have raised concern about its effectiveness. Furthermore, most previous studies examined its use in patients with light skin types, and the use of pulse dye laser in dark-skinned patients for the treatment of hypertrophic scars is not well established.
  
  
  OBJECTIVE
  The objective was to assess the role of pulsed dye laser therapy in the treatment and prevention of hypertrophic scars in Chinese persons.
  
  
  METHODS
  Twenty-nine patients (35 scars) who had scars for less than 6 months were recruited into the prevention group, and 27 patients (36 scars) who had scars for more than 6 months were recruited into the treatment arm of the study. Each received pulse dye laser treatment (585 nm, 1.5-msec pulse duration, 5-mm spot size, 7-8 J/cm(2)) for three to six treatments at 8-week intervals. Half of the scar was treated with the laser and the other half was used as a control. All patients were assessed for subjective improvement with the use of a structured questionnaire and objectively with ultrasonography for thickness and a cutometer for viscoelasticity. Scars were marked on every patient and mapped with a translucent paper at the first appointment to ensure the consistency of location. At the end of the study, 15 patients from the prevention group (15 scars) and 23 patients from the treatment group (34 scars) agreed to return for spectrophotometer assessment.
  
  
  RESULTS
  Fifty-four percent of patients in the prevention group and 66% of patients in the treatment group considered their scars to be better or much better. For both groups of patients, there was significant improvement in term of pruritics after laser treatment. For objective assessment, although scar thickness reduced significantly compared to baseline in the treatment group, such change was not significant when changes in the control side were taken into consideration. There was insignificant change in viscoelasticity. Spectrophometer assessment indicated a significant degree of lightening in the treatment group.
  
  
  CONCLUSIONS
  Our study indicated that although there was significant symptomatic improvement, there was an insignificant degree of objective improvement in terms of scar thickness and viscoelasticity in the prevention group compared to the control group. Our findings are in line with several previous controlled studies and contradict the results of several others. Such differences can be due to differences in assessment methodology, laser settings, skin type, and scar location. Suprapurpuric pulsed dye laser should not be considered as the standard of practice for the treatment and prevention of hypertrophic surgical scars especially in the chest in Asians patients.
authors.affiliation: Division of Dermatology, Department of Medicine, The University of Hong Kong, Hong Kong. hhlchan@hkucc.hku.hk
authors.forename: Henry H
authors.initials: HH
authors.lastname: Chan
authors.forename: David S Y
authors.initials: DS
authors.lastname: Wong
authors.forename: W S
authors.initials: WS
authors.lastname: Ho
authors.forename: L K
authors.initials: LK
authors.lastname: Lam
authors.forename: W
authors.initials: W
authors.lastname: Wei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002681:China; D017439:Cicatrix, Hypertrophic / Q000517:prevention & control* / Q000601:surgery*; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D008297:Male; D008875:Middle Aged