Epidermal Barrier Function
The skin's capacity to prevent transepidermal water loss and block entry of irritants, allergens, and pathogens through the stratum corneum.
Full Definition
Epidermal barrier function refers to the physical and biochemical properties of the outermost skin layers, primarily the stratum corneum, that maintain homeostasis by limiting transepidermal water loss (TEWL) and resisting external insults. Disruption of this barrier is central to the pathophysiology of conditions such as atopic dermatitis and ichthyosis. Editors will encounter this term in clinical trial reports, patient information leaflets, and cosmeceutical product reviews. It is frequently measured by TEWL instruments and described in the context of ceramide or filaggrin deficiency. The term should not be conflated with 'skin hydration', which is one downstream parameter of barrier competence.
Usage
Usage note: Use the full phrase on first mention; 'barrier function' alone is acceptable on subsequent mentions within the same document.
In Context
- "The investigational moisturiser was shown to restore epidermal barrier function within 48 hours of application." — Clinical trial results section
- "Mutations in the filaggrin gene are a well-established cause of impaired epidermal barrier function in atopic eczema." — Pathophysiology review article