Atopic eczema : the role of stratum corneum lipids in the skin barrier

Abstract

The skin barrier function strongly relies on the outermost layer of the skin, the stratum corneum (SC), which consists of dead corneocytes embedded in a highly organized extracellular lipid matrix. The lipids are thought to play a crucial role in the skin barrier function. This lipid matrix consists mainly of ceramides, cholesterol and free fatty acids in an approximately equimolar ratio. Atopic eczema (AE) is a chronic relapsing inflammatory skin disease that is characterized by dryness, erythema and pruritus. AE patients have a decreased skin barrier function as monitored with transepidermal water loss. The main objective of this thesis is to determine the SC lipid composition, lipid organization and lipid/protein ratio in AE patients and control subjects and to determine how these changes are associated with the impaired skin barrier function and disease severity of AE patients. The studies demonstrate that there is an altered lipid composition and lipid/protein ratio in non-lesional as well as lesional SC of AE patients. The changes in lipid composition result in an altered lipid organization that is associated with an impaired skin barrier function in AE patients