Skin 101: Understanding the Fundamentals of Skin Barrier Physiology-Why is This Important for Clinicians?

This article reviews epidermal barrier dysfunctions and more thoroughly discusses the stratum corneum (SC) permeability barrier, physiologic self-repair mechanisms in healthy skin, and the clinical and structural effects of an overstressed SC permeability barrier. Discussion includes epidermal barrier impairments induced by both exogenous exposures and endogenous factors such as specific dermatologic disorders. Due the plethora of skin care products on the market and the variability of their contents and vehicle formulations, this article addresses core concepts required to optimize skin care product selection, including for specific disease states such as atopic dermatitis, psoriasis, acne vulgaris, and rosacea. To summarize, the selection of skin care products is directed at maintaining SC hydration, including assisting the SC in self-repair when conditions are adverse. This approach optimizes the ability to sustain healthy skin structure, function and appearance.