Clinical evaluation of needle-free electronic pneumatic hyaluronic acid injection treatment for facial atrophic acne scars: A prospective, randomized comparative trial.

Acne scars are common but difficult to treat, and an effective new treatment strategy is desired. This prospective, split-face randomized controlled trial was designed to compare the safety and efficacy of needle-free electronic pneumatic hyaluronic acid injection (EPI-HA) treatment for acne scars. Thirty Japanese subjects with moderate to severe facial atrophic acne scars underwent EPI-HA treatment on a randomized side of their face. Three treatment sessions were carried out at 1-month intervals, and the subjects were followed-up for 3 months after the final treatment. Three months after the final treatment, 48.3% of treated sides met the criteria for success, compared with 0% for the control sides (P < 0.0001). Rolling type scars were much improved compared with boxcar types and icepick types. Satisfaction (or better) was reported by 55.2% of subjects at the 3-month follow-up after the final treatment, which was similar to the physicians' assessment. Three-dimensional in vivo imaging analysis detected significant difference in scar reductions between the treated and control sides in the mean scar area, scar depth, and maximum depth of the biggest scar at 1 and 3 months after the final treatment (all P < 0.05). In conclusion, EPI-HA treatment significantly improved rolling facial atrophic acne scars in our Japanese subjects, with minimal side effects.