Stratum corneum lipid barrier and surface lipids (SC lipid barrier)

The stratum corneum lipid barrier and surface lipids represent the outermost defensive layer of the skin, essential for maintaining homeostasis and protecting against environmental insults. The barrier is primarily composed of an extracellular lipid matrix containing ceramides, cholesterol, and free fatty acids, which are organized into lamellar sheets that prevent transepidermal water loss (TEWL) [PMID: 24656726]. Surface lipids, including sebum-derived squalene and wax esters, provide additional lubrication and antimicrobial properties [PMID: 28395308]. In diseases such as atopic dermatitis and psoriasis, the composition and organization of these lipids are significantly altered, leading to a "leaky" barrier that allows for allergen penetration and chronic inflammation [PMID: 30130616]. Pharmacological targeting of this system involves the topical application of physiological lipids to restore the barrier or the use of occlusive agents to mimic its function. Additionally, systemic treatments like isotretinoin target the production of surface lipids by sebaceous glands to treat acne [PMID: 29356148]. Understanding the complex interplay between these lipids is crucial for developing effective treatments for various dermatological conditions and improving drug delivery through the skin.

Other names

Skin lipid barrierEpidermal lipid barrierIntercellular lipid lamellaeSkin surface lipidsCutaneous lipid barrier

Restoration of the epidermal permeability barrier through lipid replenishment, occlusion to reduce transepidermal water loss, and humectancy to increase water-binding capacity.