Efficacy of Heterologous Type I Collagen Injections in Treating Atrophic Acne Scars: A Prospective Study

Treatment of acne scars includes laser therapies, microneedling, chemical peels, and dermal fillers. Herein, we sought to assess the efficacy and safety of heterologous type I collagen injections (HT1Cs) on atrophic acne scars. One hundred milligrams of HT1C were injected beneath each atrophic acne scar on patients with atrophic acne scars graded as 2, 3, or 4 according to the Goodman and Baron's acne scar grading system. Patients underwent four treatment sessions at 2-week intervals, and they were evaluated for up to week 52, using the above-mentioned grading system and a 0-10 visual analogue scale (VAS). 30 patients (9 males: 21 females; median [range] age 32 [18-50] years) were enrolled in the study. At baseline, 10 (33%), 17 (57%), and 3 (10%) patients presented with grade 2, 3, and 4 scaring. At 3-month follow-up, 7 (23%), 16 (53%), 4 (13%), and 3 (10%) of patients presented with grade 1, 2, 3, and 4 scaring, respectively. At the same visit, physicians rated the mean improvement as 6.8, while patients rated it slightly higher at 7.2. The observed improvements were sustained up to 12 months. The mean patients' satisfaction rate at 3 months was 7.4. No major adverse events were reported throughout the entire duration of the follow-up period. The results of the present study highlight the efficacy, sustainability, and safety of HT1C injections in treating atrophic acne scars.