Skin Diseases Associated with the Depletion of Stratum Corneum Lipids and Stratum Corneum Lipid Substitution Therapy

The skin is the largest organ of the body, whose main function is to protect the body against the loss of physiologically important components as well as harmful environmental insults. From the inside to the outside, the skin comprises three major structural layers: the hypodermis, the dermis and the epidermis. The epidermis contains four different sublayers, the stratum corneum (SC), stratum granulosum, stratum spinosum and stratum basale, where the barrier function of the skin mainly lies in the outermost layer of the epidermis, the SC. The SC contains corneocytes that are embedded in a lipid matrix existing in the form of lipid bilayers. The lipid bilayers are formed mainly from ceramides, free fatty acids and cholesterol, constitute the only continuous pathway across the SC and are responsible for the barrier function of the skin. However, the depletion or disturbance of SC lipids in the SC leads to a perturbation of the barrier function of the skin, and, conversely, several skin diseases such as psoriasis and atopic dermatitis are associated with the depletion of these SC lipids. Therefore, it is of paramount importance to underReceived: November 15, 2013 Accepted after revision: January 27, 2014 Published online: August 29, 2014 Prof. Dr. Dr. h.c. Reinhard H.H. Neubert Department of Pharmaceutical Technology and Biopharmaceutics Martin Luther University of Halle-Wittenberg , Wolfgang-Langenbeck-Strasse 4 DE–06120 Halle (Saale) (Germany) E-Mail reinhard.neubert @ pharmazie.uni-halle.de © 2014 S. Karger AG, Basel 1660–5527/14/0281–0042$39.50/0