Skin barrier (or Stratum corneum for the main component)

The **skin surface/protective barrier** is a multifactorial system comprised mainly of the **stratum corneum**, the outermost layer of the epidermis. It consists of flattened, dead corneocytes bound by specialized proteins (e.g., filaggrin, involucrin, loricrin) and lipids (mainly ceramides, cholesterol, free fatty acids), organized into a "brick and mortar" structure[2][3][5][6]. This physical barrier prevents water loss, blocks entry of pathogens and toxins, and supports immune surveillance. Key chemical elements such as the acid mantle and antimicrobial peptides further defend against infection and help regulate pH. A healthy barrier is essential for skin hydration, resistance to irritation, and overall skin health. Dysfunction leads to increased susceptibility to disease, including dermatitis and infection[2][4][9].

Other names

Skin surface barrierEpidermal barrierProtective skin barrierStratum corneum (main layer)

Restoration of lipid/protein composition, enhancement of hydration, reduction of inflammation, prevention of pathogenic penetration, acidification to promote homeostasis[3][6][9]