Skin barrier components

Skin barrier components encompass the structural and chemical elements of the stratum corneum, the outermost layer of the epidermis, which functions as the body's primary interface with the environment (StatPearls: NBK537164). This barrier is often conceptualized as a brick and mortar structure, where protein-rich corneocytes act as bricks and a lipid-rich extracellular matrix—comprising ceramides, cholesterol, and free fatty acids—acts as the mortar (PubMed: 18254808). Its primary biological roles include preventing transepidermal water loss (TEWL) and shielding against exogenous pathogens, allergens, and mechanical stress (StatPearls: NBK537164). Dysfunction of these components is a hallmark of various dermatological diseases, such as atopic dermatitis and psoriasis, where barrier permeability is increased (J Clin Aesthet Dermatol: PMC5608132). Pharmacological intervention typically involves non-specific topical treatments like emollients and occlusives that physically reinforce the barrier or humectants that enhance water retention, rather than binding to specific molecular receptors (PubMed: 18254808). These treatments aim to restore the skin's natural protective function and reduce inflammation associated with barrier breakdown.

Other names

Epidermal barrierStratum corneumSkin lipidsAcid mantleCorneocytes

Topical agents act via occlusion to prevent water loss, humectancy to attract moisture into the stratum corneum, or by replenishing essential lipids to restore the structural integrity of the epidermal barrier.