There are various definitions of psoriasis some of which are:

• Psoriasis is a chronic, non-infectious disease that affects mainly the skin. It is currently suspected to be
   autoimmune in origin. It commonly causes red, scaly patches to appear on the skin, although some patients have
   no dermatological symptoms.

• A non contagious disease whose main symptom is gray or silvery flaky patches on the skin which are red and
   inflamed underneath when scratched.

• A common, immune-mediated disease that results in areas of reddish or scaly plaque over different parts of the
   body.

• Psoriasis is a common skin disease that comes in different forms and varying levels of severity. It affects up to 3
   percent of populations worldwide. Most researchers agree that it is an auto-immune disease.

• A skin disease characterized by thickened, inflamed patches of skin covered by silver-gray scales. Between 10
   percent and 30 percent of people with psoriasis develop an associated arthritis referred to as psoriatic arthritis.

• It is a skin condition whereby areas are covered in pink or red colored patches with white scales. The skin cells
   multiply much faster than normal, healthy cells and the overproduction of these cells is what causes the raised
   patches of skin. Psoriasis tends to run in families.