Skin barrier (stratum corneum intercellular lipid structure)

The **skin barrier**, primarily formed by the **stratum corneum**, is a multi-layered structure at the outermost surface of the skin composed of terminally differentiated keratinocytes (corneocytes) embedded in an organized extracellular lipid matrix dominated by ceramides, cholesterol, and free fatty acids[1][2][3][5][7]. These components are arranged in stacked lamellar bilayers parallel to the skin surface, providing a robust shield against physical, chemical, and microbial insults, as well as regulating water loss[8]. Proteins (filaggrin, involucrin, loricrin, desmosomal cadherins) and specialized lipid-protein envelopes (cornified envelope and cornified lipid envelope) further add mechanical strength and impermeability. Epidermal homeostasis, immunity, and hydration are strongly dependent on skin barrier integrity, and genetic or environmental disruption of its components drives diseases such as atopic dermatitis and other forms of skin inflammation or infection[1][5][7].

Other names

stratum corneum barrierepidermal barriercorneocyte membranecornified envelopeSC barrier

Restoration of lipid balance and barrier integrity (ceramides, cholesterol, fatty acids supplement barrier lipids) Anti-inflammatory action (corticosteroids reducing inflammation that otherwise impairs barrier) Prevention of water loss (occlusive agents reduce TEWL)