Intradermal Injection of Poly-d, l-Lactic Acid Using Microneedle Fractional Radiofrequency for Acne Scars: An Open-Label Prospective Trial

BACKGROUND Treatment with filler injections using a microneedle fractional radiofrequency (MFRF) device is a promising modality with proven efficacy for acne scar treatment. OBJECTIVE To investigate the efficacy and histologic differences of intradermal injection of a filler (poly-d, l-lactic acid, PDLA) using an MFRF device for the treatment of acne scars. METHODS Patients with acne scars on both cheeks were included. Poly-d, l-lactic acid was injected via the MFRF device every 4 weeks for a total of 4 sessions. Patients were evaluated using the grading system for acne scars before each session, as well as personal satisfaction. For histologic evaluation, 2 patients (who consented) underwent a skin biopsy from the upper arm before and after the same single session. RESULTS After the final session, the acne scar grading (échelle d'évaluation clinique des cicatrices d'acné) scale and visual analog scale for evaluation of satisfaction showed improvement compared with initial assessment (36.99% and 79.65% respectively [p < .001, respectively]). For histologic evaluation, biodegradation of PDLA materials and increase in collagen and elastic fibers were observed after 5 months of treatment. CONCLUSION Intradermal injection of PDLA using the MFRF device could be used as an effective treatment with fewer side effects in acne scar patients with Fitzpatrick skin type III-IV.