Simultaneous versus sequential fractional CO₂ laser and subcision combination for management of post‐acne atrophic scars: A split‐face comparative study

Background A combination of fractional CO 2 laser and subcision is usually employed for the treatment of post‐acne atrophic scars. However, the efficacy and safety of both simultaneous and sequential combination therapies should be explored. Aims To compare the efficacy and safety of simultaneous and sequential fractional CO 2 laser and subcision combination therapies for post‐acne atrophic scars. Patients and Methods This single‐blind, split‐face clinical trial included 34 patients with post‐acne atrophic scars at our institution. Each patient underwent three sessions of subcision combined with fractional CO 2 laser, with a 1‐month interval between each session. The left side of the face was treated with simultaneous combination therapy, whereas the right side was treated with sequential combination therapy. Treatment efficacy was assessed at 4, 8, and 12 weeks; and 3 and 6 months after the last session. Results Simultaneous and sequential treatments demonstrated comparable efficacy. Regarding the adverse events, the side of the face undergoing simultaneous treatment experienced longer swelling duration, higher pain levels during laser treatment, and shorter downtime. Conclusions Despite the longer swelling time and higher pain levels during laser treatment in the simultaneous treatment side, the effectiveness and satisfaction level of the CO 2 fractional laser and subcision for treatment of the acne scars were comparable between the two combinations, with a shorter downtime for the simultaneous than for the sequential combination therapy.