Skin lesions

The skin is the largest organ of the body, with a surface area of between 10 000 and 18 000 cm2 in the average adult, accounting for approximately 15 per cent of the total body weight. The multiple functions of the skin allow humans to adapt to a wide variety of environmental conditions. An important aspect of the function of skin is that of protecting deeper structures. It also has an important role in thermoregulation, metabolism (vitamin D production), immunological defence, a sensory interface with our surroundings and a psychological expression of an individual to their surroundings. The skin as an organ is vulnerable to a wide variety of diseases and conditions. Ageing is accompanied by a loss of elasticity and wrinkling. Degenerative changes result from excessive exposure to ultraviolet radiation and environmental factors. Reactions to chemicals and drugs are also common, and the skin is probably susceptible to more different types of turnouts than any other organ. Lesions arise from any of the structures that are present in the skin.