Psoriasis is a chronic recurring skin disease. In principle, people of all ages can get psoriasis, but the early onset form of the disease is mostly seen in 16 to 22 year-olds and the late onset form strikes those between the ages of 50 and 60.
Psoriasis is derived from the Greek word 'psora', which means itch.
Around two per cent of the population have psoriasis to a greater or lesser degree. It is thought that the underlying problem is that new skin cells are produced too quickly and rise to the surface before the old skin cells have had time to die off and be scrubbed away. The result of this overproduction of skin cells is red and raised patches on the skin. The overproduction of skin cells may be due to a problem with the immune system. These T cells cause the skin to become inflamed by releasing chemicals that cause the body to react as if it was being attacked by an infection - this is known as the inflammatory cycle.