Background: There is a lack of randomized split-face studies investigating treatments for dermatosis papulosa nigra (DPN) in dark skin.
Objective: To compare the efficacy, safety, and tolerability of potassium-titanyl-phosphate (KTP) laser with efficacy, safety, and tolerability of electrodesiccation in the treatment of DPN in subjects with Fitzpatrick skin phototypes IV to VI.
Methods: Fourteen subjects with Fitzpatrick skin phototypes IV to VI were randomized to receive two KTP laser treatments 4 weeks apart to half of the face. The contralateral half received two electrodesiccation treatments 4 weeks apart. Response was evaluated by photography reviewed by blinded dermatologists at 4 weeks after the second treatment. A treatment quality questionnaire about side effects and cosmetic outcome was also administered.
Results: Difference in improvement of DPN between the KTP side and the electrodesiccation side per each rater (p=.99, p=.54) and per raters combined (p=.50) did not reach statistical significance. There was no treatment difference for subjective effectiveness (p=.06) or subjective confidence improvement (p=.99), although there was a significant treatment difference for subjective discomfort (p=.002) in favor of KTP. Both treatments were well tolerated without significant adverse effects.
Conclusions: Although treatment of DPN with KTP laser and electrodesiccation are comparable in efficacy, KTP laser is preferable for patient comfort.