Atrophic Scars, Maturation Time and Therapeutic Outcomes Following Microneedling: A Post Hoc Analysis of a Randomized Clinical Trial

ABSTRACT Background Linear atrophic scars, resulting from surgical or traumatic injuries, are characterized by dermal depression, pigmentation changes, and psychosocial burden. While their early treatment has been hypothesized to yield better outcomes due to heightened tissue responsiveness during the proliferative healing phase, optimal timing for therapeutic intervention remains unclear. Objective To evaluate whether the duration of scar evolution influences clinical, ultrasound, histological, and patient‐reported outcomes following microneedling treatment of linear atrophic scars. Methods This was a post hoc analysis of a randomized controlled trial involving 24 patients with linear atrophic scars treated with microneedling. Scar maturation time was evaluated in relation to outcomes including erythema, hypopigmentation, hyperpigmentation, brightness, scar relief, and patient‐reported satisfaction. Evaluations were performed using standardized scales by dermatologists and self‐reported improvement. Paired t ‐tests were conducted to compare pre‐ and post‐treatment scores. The means of the deltas between pre‐ and post‐treatment values were compared across scar age strata (≤ 36 months vs. > 36 months, based on the median) using independent‐samples t ‐tests to assess whether scar age significantly influenced treatment response. Results All clinical indicators showed statistically significant improvement following microneedling ( p < 0.05), regardless of scar age. There were no significant differences ( p > 0.05) in the mean deltas between the two scar age groups, suggesting that scar age did not significantly influence treatment response. Due to the exploratory nature of the study and the small sample size, uncorrected p ‐values were reported to avoid increasing Type II error, acknowledging an increased risk of false‐positive findings due to multiple comparisons. Conclusion Within the parameters of this exploratory analysis, scar age did not significantly influence the clinical or patient‐reported response to microneedling in linear atrophic scars, suggesting that microneedling may be effective across different stages of scar maturation. However, larger prospective trials with extended follow‐up are warranted to validate these results and determine the optimal timing for intervention.