JAMA Dermatology Study Highlights
The prospective study included 23 nevi from 20 patients attending a referral hospital. Half of each nevus was protected by either a physical barrier or a sunscreen. Lesions were completely irradiated by a single dose of UV-B. Outcomes were measured through vivo examinations before and 7 days after irradiation and histopatholoic-immunopathologic was evaluated after excision on the seventh day.
According to the study results, the most frequent clinical changes after UV radiation were pigmentation, scaling, and erythema; the most frequent dermoscopic changes were increased globules/dots, blurred network, regression, and dotted vessels. Both physical barrier-and sunscreen-protected areas showed some degree of these changes. The only difference between both barriers was more enhanced melanocytic activation and regression features in the sunscreen group. No phenotypic features were found to predict a specific UV-B response.
“Both physical barriers and sunscreens can partially prevent UV-B effects on nevi. Subclinical UV radiation effects, not always associated with visible changes, can develop even after protection. Sunscreens are not quite as effective as physical barriers in the prevention of inflammatory UV-B-induced effects,” the authors notes.
JAMA Dermatol. Published May 8, 2013. doi:10.1001/jamadermatol.2013.398.