There has been a huge surge in interest in the way our skin functions over the last 20 years. This has led to a growth in knowledge that may aid rational drug design and lead to advances in the treatment of skin diseases.

The skin is our largest body organ, covering about two square metres and weighing around 5 kilogrammes. It consists of two layers of tissue above a base of fatty tissue which is connected to the skeleton beneath. The epidermis is the visible, hard outer layer of the skin and the relative levels of compounds in this layer are variable which can affect its quality. For example aged or sun-damaged skin has high levels of cholesterol and a diet deficient in polyunsaturated fatty acids can result in water loss and scaly skin. The second layer, the dermis, is the skin's 'shock absorber'. It contains cells of the immune system, some of which can trigger allergic reactions. It is also made up of a large percentage of collagen which is important for wound healing. Interspersed within the dermis are hair follicles, nails, blood vessels, glands and nerves.

Desmond Tobin at the University of Bradford, UK, became interested in the science of skin during his studies into a hair-loss disorder called alopecia areata. He views the skin as a 'gate-keeper' between our internal and external environments and continues to be 'hugely impressed by the sheer complexity of the skin' and its 'critical role in human health and well-being.' 

Amongst many others, the most obvious role of the skin is as a barrier protecting us from continual exposure to elements such as UV radiation, heat, mechanical force, chemicals and biological agents. A deeper understanding of skin biochemistry can only help in the development of future therapies for skin conditions such as contact dermatitis and skin cancer.

Celia A. Clarke