Histological studies of facial acne and atrophic acne scars treated with a bipolar fractional radiofrequency system.

Various fractional radiofrequency (FRF) treatments have demonstrated significant beneficial effects and minor side-effects on atrophic acne scars and acne vulgaris by creating micro-thermal injuries in the skins. However, histological studies to identify the precise mechanism responsible for the success of bipolar FRF treatments are lacking. In this study, six human subjects with these diseases were histologically analyzed after treatment with a bipolar FRF system (eMatrix; Syneron, Yokneam, Israel) and the effects of multiple passes were compared. Histopathological results showed that two-pass FRF treatment created deeper dermal thermal injury zones compared to one-pass treatment. Periadnexal collagen was coagulated, as well as that in the sebaceous glands, as evaluated in all cases with two-pass FRF treatment. No severe side-effects were observed after treatment. Our experience suggests that the level of dermal thermal injury is directly related to the number of passes, and that a large benefit of this treatment for these diseases is the preservation of adnexal structures.