Skin Barrier Compromise: A Central Early Event in Ultraviolet Radiation-Induced Skin Pathogenesis

BACKGROUND: Ultraviolet radiation (UVR) is a major environmental stressor to the epidermis. Increasing evidence indicates that barrier impairment is an early and central event that links DNA injury and oxidative injury with inflammatory, immune, and microbiome changes. SUMMARY: This review synthesizes recent mechanistic advances in UVR-induced epidermal barrier injury and the resulting downstream responses. It evaluates emerging multifunctional photoprotection approaches that combine ultraviolet filters with biologically active components such as antioxidants and photolyase containing systems that may support the resolution of DNA lesions, and it highlights early microbiome conscious strategies alongside key evidence gaps. KEY MESSAGES: A barrier-centered framework can unify diverse mechanisms of UVR damage and inform more biologically grounded photoprotection. Clear barrier-related endpoints and stronger clinical evidence are needed to determine which adjunctive strategies provide meaningful benefit beyond traditional ultraviolet filtering.