Efficacy and Safety of Non‐Cross‐Linked Hyaluronic Acid Mesotherapy for Post‐Acne Erythema: A Split‐Face, Prospective, Randomized, Single‐Center Trial

BACKGROUND: Post-acne erythema (PAE) is one of the most common inflammatory sequelae of acne. Although various therapeutic approaches are currently available, many are limited by suboptimal efficacy, poor tolerability, or high costs. This trial aims to evaluate the clinical efficacy and safety of non-cross-linked hyaluronic acid (HA) mesotherapy for the treatment of PAE. METHODS: A total of 25 patients aged 18-35 years with clinically diagnosed PAE and bilaterally symmetrical facial lesions were enrolled. Three treatment sessions were performed at 4-week intervals. The primary outcome was the Clinician Erythema Assessment Scale (CEAS) score assessed at baseline and week 12. Secondary endpoints included the Dermatology Life Quality Index (DLQI), Patient Self-Assessment (PSA), VISIA skin analysis (red areas, pores, texture), CK measurement parameters (erythema index, melanin index, skin hydration, transepidermal water loss), dermoscopic imaging, adverse effects, and relapse. RESULTS: Finally, 23 patients completed all treatment sessions. By week 12, the mesotherapy group showed significantly lower CEAS scores compared to the control group. In addition, patients in the mesotherapy group reported higher satisfaction levels. Improvements in red areas, pores, texture, erythema index, skin hydration, transepidermal water loss, and dermoscopic imaging were also more marked in the mesotherapy group. There was a significant change in the DLQI score, too. No serious adverse events or erythema flares occurred during the study. Among the 23 patients who completed the trial, only one experienced acne relapse. CONCLUSION: According to the results of this study, non-cross-linked HA mesotherapy is a promising and useful therapeutic option for PAE.