Defective skin barrier function

In normal, healthy skin, the outer layer of the epidermis, the stratum corneum is made up flattened dead cells called corneocytes held together by a mixture of lipids and proteins. The stratum corneum and, in particular, the lipid layer are vital in providing a natural barrier function that locks water inside the skin and keeps allergens and irritants out. In people with eczema, the barrier function is defective, which leads to dry skin. As the skin dries out, it cracks allowing allergens and irritants to penetrate.8

It can be helpful to think of the skin as a brick wall, in which mortar (lipids) fills the gap between the bricks (corneocytes).

Eczema is like a dry stone wall, where the mortar is missing, so water and dirt are able to penetrate the wall.

skin barrier diagram

Adapted from Cork MJ8 and Buxton PK9

The first step in managing eczema is to restore the skin barrier function, to reduce the frequency and severity of flare-ups. To learn more about complete emollient therapy, click here.

References:
  1. 8.Cork MJ (1997) The Importance of Skin Barrier Function. J Dermatol Treat, 8, S7-S13
  2. 9.Buxton PK (1998) ABC of Dermatology. 3rd edition. London, BMJ Publishing Group.

Date of preparation: May 2009 / Code: E&D 09-002