Intradermal Local Injection of Autologous Cell-Free Fat Extract for the Treatment of Refractory Postinflammatory Hyperpigmentation

Abstract

Current treatment modalities for postinflammatory hyperpigmentation (PIH) often fall short in delivering satisfactory results for some patients. Therefore, this study aimed to assess the efficacy and tolerability of autologous cell-free fat extract (CEFFE) in the treatment of PIH. We enrolled 15 patients with PIH and administered them with five intracutaneous CEFFE injections, each at a two-week interval. Evaluation included efficacy assessment using objective (standard two-dimensional photos, VISIA®-photos, brown spot (BS) index, lesion lightness, lesion color, and trans-epidermal water loss) and subjective (Global Aesthetic Improvement Scale and Likert satisfaction scale) parameters and tolerance assessment. Following CEFFE treatment, significant reductions were observed in the BS index ( $p<0.05$ ) and transepidermal water loss ( $p<0.05$ ), while skin lightness and lesion color showed significant improvements ( $p<0.05$ ) at the 12-month follow-up. Subjectively, 93.33% of patients reported improved or greatly improved conditions after 12 months of treatment. Transient local bruising and stinging were the only observed treatment-related adverse events, with no serious complications reported. These findings demonstrate that intradermal injections of CEFFE are well-tolerated and effective for the treatment of PIH. This trial is registered with ChiCTR2000039381.