Fractional CO₂-laser versus microneedle radiofrequency for acne scars: A randomized, single treatment, split-face trial

Background: Ablative fractional CO₂ laser (AFL) is an established first-line energy-based treatment for acne scars. Microneedle radiofrequency (MNRF) is an emerging treatment, also targeting the skin in fractions. No studies have so far compared AFL with MNRF for acne scars in a direct controlled, side-by-side comparison. In this study, we compared AFL and MNRF treatments for acne scars in a randomized split-face trial with blinded response evaluation, objective measures, and patient-reported outcomes. Study Design/Materials and Method: Fifteen patients with moderate to severe acne scars were included. At baseline each patient had two similar test areas identified, these were randomized to receive a single treatment with either AFL or MNRF. Standardized multilayer techniques were applied with AFL and MNRF, first targeting the scar base, thereafter the entire scar area. Outcome measures included blinded evaluation of clinical improvement of scar texture (0–10 scale) at 1- and 3-months follow-up, local skin reactions (LSR), pain according to Visual Analogue Scale (VAS), skin integrity quantified by transepidermal water loss, and patient satisfaction. Results: Fifteen patients completed the study with a median test area size of 24.6 cm² (interquartile range [IQR] 14.9–40.6). A single treatment with AFL or MNRF equally resulted in a median 1-point texture improvement after 3 months follow-up (p < 0.001). Best responders achieved up to a 3-point improvement (n = 3 test areas, 10% of treatment areas). Erythema and loss of skin integrity was more intense after AFL compared with MNRF after 2–4 days (p < 0.001). Patients reported MNRF (VAS 7.0) to be significantly more painful than AFL (5.5) (p = 0.009). Patients were generally satisfied with the overall outcome on a 10-point scale at median 6 for both treatments (IQR 5–7). Conclusion: AFL and MNRF treatments are equally effective at improving texture in skin with acne scars. AFL resulted in more pronounced LSRs whereas MNRF was more painful. Patients were generally satisfied with the overall outcome.