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.