Psoriasis is an inherited disorder of the skin, which causes red, scaling bumps and patches on the skin. It is a chronic disorder, which means that the symptoms come and go throughout a person's life.
Psoriasis is an inherited disease that causes an increase in skin cells on the outer layer of the skin. In a healthy individual, skin cells mature and shed from the surface of the body about every 28 days. People with psoriasis shed skin cells every 3 to 4 days. The excess skin cells build up and form the skin lesions of psoriasis.
The exact cause of psoriasis is unknown, but it is commonly believed that the body's immune system triggers the rapid growth and shedding of skin cells. Several genes have been linked to psoriasis, which tends to run in families. However, many people with psoriasis have no family history of the disease.
Certain factors seem to trigger plaque development in people with psoriasis. Suspected triggers include the following:
A person can develop psoriasis at any age. However, it most often develops in two age ranges. The first is between 16 and 22 years of age, and the second is between 57 and 60 years of age. It affects men and women equally and is seen in all races. However, psoriasis is more common in people of Western European and Scandinavian ancestry.