During the last decade there has been tremendous advancement in our understanding of not only the structure, composition and function of the stratum corneum, but also in its formation and the epidermal differentiation factors responsible for mediating cellular changes in keratinocytes during their journey from the basal layer to the granular layer. Moreover, the structural and biochemical changes that occur in stratum corneum quality and function have received much attention. This short paper will review some of the research conducted over the past decade on our understanding of the pathophysiology of dry skin.
Stratum Corneum Barrier Lipid Composition and Structure
The lipid-enriched intercellular spaces of the stratum corneum constitute the primary barrier to water loss (Figure 1). Not only are the amount of lipids or the correct equimolar ratios of the major lipid species important (ceramide: cholesterol: fatty acids), but the precise ceramide chemical composition and physical organization of the total lipid matrix is vital for a healthy barrier.