P02 Topical retinoids for the treatment of photodamage in Latino skin

Abstract Introduction and aims Chronic sun exposure is a major contributor to photodamage, leading to significant changes in the skin’s appearance and alterations in the dermal extracellular matrix, particularly degradation of fibrillin-rich microfibrils (FRM) at the dermopidermal junction. All-trans retinoic acid (ATRA) is the gold standard for treating photodamage, with proven efficacy in both White and Black skin. However, efficacy of topical retinoids in skin of Latino individuals, whose skin tones range from light to dark, remain unexplored. The aim of this study was to assess the impact of ATRA and cosmetic retinol (ROL) on epidermal and dermal parameters of photodamage in sun-exposed Latino skin. Methods Using the Manchester Patch Test Assay, 0.025% ATRA (n = 4) and 0.3% ROL (n = 4) were applied under occlusion to dorsal forearm skin of healthy, photodamaged Latino volunteers (19–36 years) for 12 days. Skin biopsies were obtained from treated and untreated sites and processed for histological analysis. Results ATRA and ROL induced significant epidermal thickening, increasing by 72.9% (P < 0.05) and 108.7% (P < 0.01), respectively. Similarly, both treatments led to greater numbers of Ki67 positive keratinocytes, compared with untreated skin (ATRA: 5.5 vs. 2.7 cells per field; P < 0.05; ROL: 6.2 vs. 2.1 cells per field; P < 0.01). Dermal remodelling was evident following both treatments, with significant restoration of the FRM network at the dermoepidermal junction (ATRA: P < 0.01; ROL: P < 0.01). Conclusions ATRA and cosmetic ROL are effective in improving histological parameters of photoaged Latino skin, inducing similar epidermal changes and dermal remodelling. These findings suggest that both treatments may be viable options for the repair of photodamage across a broad spectrum of skin tones. Further investigation is needed to assess their long-term effectiveness in daily use.