Background and objective:
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).
Results:
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.
Conclusion:
The epidermal thickness is unimportant to the purpuric reaction after pdl treatment.