Psoriasis is a relatively common skin disorder that affects as much as 2 percent of the U.S. population. It is a chronic (continues over time) condition that occurs primarily in adults.

This disorder often appears as red patches covered by silvery scales that can be itchy; however, this is not always the case. Sometimes a biopsy (small sample of tissue) needs to be taken to confirm or rule out psoriasis. A related condition called psoriatic arthritis affects between 10 and 20 percent of those with psoriasis.

Psoriasis is a genetic disorder that is not contagious. It is an autoimmune disorder, which means it appears and spreads when part of the immune system becomes too active. This overactivity causes skin cells in certain areas of the body to multiply rapidly, causing distinctive buildups called plaques. The back, knees and scalp are common sites for plaques. Psoriasis can spread, possibly in response to infection, dry skin and other triggers. It can also go into remission (become inactive and shrink).

Sometimes joint pain accompanies psoriasis. This pain is called psoriatic arthritis. It often includes swelling and tenderness of the affected joints. The ends of the fingers and toes are common sites for psoriatic arthritis, but in more severe cases, it can involve many joints and even the spine.

Psoriasis is a chronic, inflammatory autoimmune skin disease that is controllable, but not curable. Indiana University Health dermatologists have specialized training and extensive experience diagnosing and treating psoriasis and psoriatic arthritis. We see a large number of people with psoriasis ranging from a few, minor spots to large, disfiguring patches.