Psoriasis is a common, non-contagious (not infectious) skin condition and is caused by an over-active immune system. In contrast to normal, unaffected areas of skin, which develop new skin cells every month to replace older, surface skin cells that shed or flake off, with psoriasis, new skin cells form within days rather than weeks. This rapid growth causes dead skin cells to accumulate on the skin’s surface, resulting in thick patches of red, dry, scaly skin that are often itchy and flaky. The most common type is known as plaque psoriasis, and it can appear as a small patch of affected skin, or cover an extended area.
For some people psoriasis is a constant nagging discomfort, while for others symptoms can improve and worsen from time to time. It is not unusual for psoriasis to spontaneously clear for years and stay in remission only to re-appear again many years later. Many people note a worsening of their symptoms in the colder winter months.
Children and babies can get psoriasis, but it is more common in adults. The condition cannot be transmitted to others by the touching of skin affected by psoriasis.
Psoriasis can appear anywhere on the body, but most often affects the skin of the elbows, knees, scalp and lower back. It tends to be more common in areas of friction, rubbing or injury. It can also affect the nails.