Treatment effect of ultra-pulse dynamic CO₂ laser and comedone extractor in dense comedones: a prospective, randomized, split-face, evaluator-blind, controlled clinical trial

Clearance of comedone is challenging in the treatment of acne, as it is very likely to develop into inflammatory lesions. However, there is lack of effective treatments for dense comedones. Comedone extractor has been widely employed by dermatologists, but the effect is temporary and may cause irritation. CO₂ laser is a potential method for dense comedones, but the efficacy and safety need to be explored. In this single-center, randomized, single-blind, self-controlled study, the faces of patients with dense comedones were randomly assigned into two sides receiving either ultra-pulse dynamic CO₂ laser or comedone extraction at an interval of 2 weeks for 4 sessions. After 4 treatments, the average comedone reduction rate of the CO₂ laser was 64.49%, which was higher than that by the extractor (46.36%) (P <.001). 79.16% of the patients reached over 50% reduction by CO₂ laser, while only 37.5% on extractor treated side reached 50% clearance. Texture index, porphyrin index, red zone, erythema index, and transepidermal water loss decreased after both treatments, and CO₂ laser showed more improvement. There was no difference in hydration index and melanin index between the two treatments. No permanent or severe side effects were observed on both sides. The CO₂ laser showed higher comedone clearance with lower pain scores than the comedone extractor.