Psoriasis is a chronic autoimmune disorder and the most common type is plaque psoriasis, in which raised, red skin patches are covered by flaky, silver-white patches of dead skin, known as scales and occur most frequently on the scalp.
Psoriasis develops when a person’s immune system has faulty signals that tell skin cells to grow too quickly. New skin cells form in days rather than weeks and the body does not shed these excess skin cells. The skin cells pile up on the surface of the skin, causing patches of psoriasis to appear.
Usually, signs of this autoimmune disorder appear between the ages of 15 and 35, although people of all ages can be affected. Current research indicates that psoriasis is most likely an inherited disorder—psoriasis patients have a family member with the same disease or another autoimmune disorder.