Stratum corneum (skin surface barrier) (SC (Stratum corneum))

The skin surface barrier is primarily the function of the stratum corneum, the outer layer of the epidermis, composed of densely packed corneocytes (protein-rich bricks) embedded within lipid layers (mortars) made mainly of ceramides, cholesterol, and fatty acids[1][2][3][4][5]. This barrier prevents dehydration by minimizing transepidermal water loss, protects against penetration by pathogens and toxins, regulates skin pH and supports the skin microbiome, and serves as the body’s primary interface with the environment[1][2][3][4][5]. Disruption of this barrier is implicated in inflammatory skin diseases, infection, and allergic sensitization, and is targeted therapeutically by moisturizers, topical drugs, and newer biologics[2][4][5]. Assessment of skin barrier integrity involves TEWL measurement, corneometry, and tape stripping for molecular analysis[1][2][4]. Barrier repair remains a key focus in dermatological and cosmetic product development[4][6].

Other names

skin barrierepidermal barrierstratum corneum barriercutaneous barrier

Direct restoration of lipid matrix (emollients/moisturizers replace lost ceramides, cholesterol, fatty acids); Anti-inflammatory action to reduce cytokine-mediated barrier disruption (corticosteroids, calcineurin inhibitors, biologics); Increased hydration to promote enzymatic activity and normal barrier formation