Fractional carbon dioxide laser combined with subcision for the treatment of three subtypes of atrophic acne scars: a retrospective analysis.

Fractional carbon dioxide (CO2) laser combined with subcision has been widely used for the clinical treatment, but the efficacy of the combined therapy on three types of atrophic acne scars remains unreported. This retrospective study analyzed the clinical data of 413 patients with atrophic acne scars, treated with fractional CO2 laser combined with subcision in the combined group and with fractional CO2 laser in the control group. The treatment efficacy was evaluated by the Investigator's Global Assessment (IGA) and the Échelle d'évaluation clinique des cicatrices d'acné (ECCA). We reported adverse reactions such as erythema, lump, skin sensitivity, acne recurrence, and hyperpigmentation that occurred in both treatment groups. The treatment efficiency of the combined group was significantly higher than that of the control group (P < 0.001). Among the three subtypes of atrophic acne scars, the ECCA scores in the combined group of boxcar-type and rolling-type scars after treatment were lower than those in the control group (P = 0.041, P < 0.001, respectively), and no statistical difference in scores between the two groups for icepick-type scars was seen (P = 0.062). There was no statistical difference in adverse reactions between the two groups (P = 0.361). Fractional CO2 laser combined with subcision is more effective than fractional CO2 laser in the treatment of boxcar-type and rolling-type scars, but there is no significant difference in the treatment of icepick-type scars.