Haedersdal M, Bech-Thomsen N, Therkildsen P, Poulsen T, Wulf H C
Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Denmark.
Lasers Surg Med. 1998;22(3):159-64. doi: 10.1002/(sici)1096-9101(1998)22:3<159::aid-lsm3>3.0.co;2-o.
To clarify whether epidermal thickness is of importance to the purpuric reaction from treatment with the pulsed dye laser (PDL).
STUDY DESIGN/MATERIALS AND METHODS: Fifteen fairly pigmented volunteers were laser treated in two test regions of varying epidermal thicknesses: normal buttock skin and ultraviolet B (UVB)-exposed buttock skin. Laser treatments were performed with the flashlamp-pumped PDL (585 nm). Fluences ranged from 3-6.5 J/cm2, spot size was 7 mm, and each volunteer received at least six fluences in each treatment region. Assessment of the response was based on clinical evaluation (threshold dose to purpura 10 minutes and 1 day after treatment) and skin reflectance-evaluated redness (1 and 6 days, 2 and 6 weeks after treatment).
The total epidermal thickness differed between the unexposed buttock skin (median, 72.7 microm) and the UVB-exposed buttock skin (87.2 microm) (P < 0.01). There was no correlation between the epidermal thickness and the threshold dose to induce purpura 10 minutes and 1 day after laser exposure. Skin reflectance revealed no correlation between the epidermal thickness and the skin reflectance evaluated redness on 1, 6 days, and 2 weeks postoperatively. A dose-response relation was seen within the two test regions; 6 weeks after laser exposure, there was no remaining laser-induced skin redness.
The epidermal thickness is unimportant to the purpuric reaction after PDL treatment.
明确表皮厚度对于脉冲染料激光（PDL）治疗所致紫癜反应是否重要。
研究设计/材料与方法：对15名肤色较深的志愿者在两个表皮厚度不同的测试区域进行激光治疗：正常臀部皮肤和紫外线B（UVB）照射后的臀部皮肤。使用闪光灯泵浦的PDL（585nm）进行激光治疗。能量密度范围为3 - 6.5J/cm²，光斑大小为7mm，每位志愿者在每个治疗区域接受至少六种能量密度的治疗。基于临床评估（治疗后10分钟和1天出现紫癜的阈值剂量）和皮肤反射率评估的发红情况（治疗后1天和6天、2周和6周）对反应进行评估。
未照射的臀部皮肤（中位数，72.7微米）和UVB照射后的臀部皮肤（87.2微米）之间的表皮总厚度存在差异（P < 0.01）。激光照射后10分钟和1天，表皮厚度与诱发紫癜的阈值剂量之间无相关性。皮肤反射率显示，表皮厚度与术后1天、6天和2周时皮肤反射率评估的发红情况之间无相关性。在两个测试区域内均观察到剂量 - 反应关系；激光照射6周后，无激光诱发的皮肤发红现象残留。
表皮厚度对PDL治疗后的紫癜反应并不重要。
