Skin epidermal barrier

The skin epidermal barrier is a complex multi-layered structure, primarily residing in the stratum corneum, that functions as a critical interface between the body and the external environment. It consists of a brick and mortar arrangement where protein-rich corneocytes are embedded in a lipid matrix composed of ceramides, cholesterol, and free fatty acids (StatPearls, NBK537164). This barrier prevents excessive transepidermal water loss (TEWL) and protects against pathogens, allergens, and UV radiation (PubMed, 29947137). In diseases like atopic dermatitis and psoriasis, the barrier is compromised due to genetic factors (e.g., filaggrin mutations) or inflammatory cytokines, leading to increased sensitivity and chronic inflammation (NIH, PMC5967208). Pharmacological interventions target this barrier either directly through topical emollients and lipid replacement therapies or indirectly by inhibiting pathways that degrade barrier integrity. While not a single molecular target, it represents a critical physiological endpoint for many dermatological interventions.

Other names

Stratum corneum barrierEpidermal permeability barrierCutaneous barrierSkin barrier

Drugs targeting the skin epidermal barrier work by providing an occlusive seal to prevent water loss, replenishing essential lipids like ceramides, or modulating the immune environment to promote the expression of structural proteins such as filaggrin and loricrin (StatPearls, NBK537164).