INFLUENCE OF UVB THERAPY ON DERMOSCOPIC FEATURES OF ACQUIRED MELANOCYTIC NEVI

Background: Exposure to UV radiation can lead to clinical, histologic, and ultrastructural changes in acquired melanocytic nevi. Objective: We investigated whether UVB therapy can induce changes in melanocytic nevi detectable by dermoscopy. Methods: Eighty acquired melanocytic ne vi of 13 patients (10 females, 3 males; mean age, 28 years; range, 13 to 62 years) undergoing UVB therapy were documented under standardized conditions by means of a Dermaphot apparatus before and at the end of suberythemal UVB therapy. The mean duration of therapy was 8 weeks (r ange, 2 to 17 weeks) and the mean total UVB dose was 1120 mJ/cm(2) (ra nge, 247 to 2771 mJ/cm(2)). During UV irradiation, 40 nevi were left u nprotected and 40 nevi were protected from UV exposure in a randomized manner. Color dermoscopic images of nevi before and after UVB therapy were projected side by side and examined blindly by five investigator s. Fifteen different features were evaluated in the nevi. Results: Unp rotected nevi became more irregular (p less than or equal to 0.01) and darker brown (p less than or equal to 0.03) by the end of the therapy , whereas the protected nevi showed no significant changes. Conclusion : Suberythemal WE therapy can lead to changes in the dermoscopic image of acquired melanocytic nevi, presumably by activating melanocytes.