A Novel Peel to Prevent Post-Inflammatory Hyperpigmentation After CO₂ Resurfacing for Acne Scars

Atrophic acne scars are a common dermatological concern, often requiring fractional carbon dioxide (CO₂) laser resurfacing for effective treatment. However, in darker skin types (Fitzpatrick III-V), the high risk of post-inflammatory hyperpigmentation (PIH) remains a significant limitation, affecting treatment outcomes.

This study evaluates the efficacy of a novel pre- and post-treatment peel in reducing PIH following fractional CO₂ laser resurfacing, particularly in higher Fitzpatrick skin types. The primary outcome was the incidence and severity of PIH, while secondary outcomes included healing time and changes in acne scar grading.

Twenty-nine patients underwent fractional CO₂ laser resurfacing, with the study group (n = 15) receiving adjunctive peeling treatment before and after the procedure. PIH severity was assessed using the Post-Inflammatory Hyperpigmentation Area and Severity Index (PIHASI) at Week 6. Healing time and changes in acne scar grading (Goodman and Baron scale) were also analyzed.

The peel-treated group had a lower median PIHASI score (0.0 [IQR: 0.0-0.2]) than the no-peel group (0.2 [IQR: 0.2-0.4]) at Week 6. The Mann-Whitney U test showed a statistically significant difference (z = 2.427, p = 0.015, exact p = 0.016). Re-epithelialization time was comparable (Day 6.4 in peel group vs. Day 6.2 in control group), and no significant difference was observed in acne scar improvement (scar reduction: 1.27 ± 0.59 vs. 1.36 ± 0.63, p = 0.694). No adverse events were reported.

The novel peel effectively reduces PIH risk following fractional CO₂ laser resurfacing without affecting scar outcomes. While it offers a promising approach for Fitzpatrick III-V patients, further studies with larger cohorts are needed to validate its long-term efficacy.