What is psoriatic arthritis?

Joint pain, stiffness, and swelling are the main signs and symptoms of psoriatic arthritis. They can affect any part of your body, including your fingertips and spine, and can range from relatively mild to severe. In both psoriasis and psoriatic arthritis, disease flares may alternate with periods of remission.

No cure for psoriatic arthritis exists, so the focus is on controlling symptoms and preventing damage to your joints. Without treatment, psoriatic arthritis may be disabling.

Symptoms

Both psoriatic arthritis and psoriasis are chronic diseases that get worse over time, but you may have periods when your symptoms improve or go into remission alternating with times when symptoms become worse.

Psoriatic arthritis can affect joints on just one side or on both sides of your body. The signs and symptoms of psoriatic arthritis often resemble those of rheumatoid arthritis. Both diseases cause joints to become painful, swollen, and warm to the touch.

Causes

Psoriatic arthritis occurs when your body's immune system begins to attack healthy cells and tissue. The abnormal immune response causes inflammation in your joints as well as overproduction of skin cells.

It's not entirely clear why the immune system attacks healthy tissue, but it seems likely that both genetic and environmental factors play a role. Many people with psoriatic arthritis have a family history of either psoriasis or psoriatic arthritis. Researchers have discovered certain genetic markers that appear to be associated with psoriatic arthritis.

Physical trauma or something in the environment — such as a viral or bacterial infection — may trigger psoriatic arthritis in people with an inherited tendency.

Complications

A small percentage of people with psoriatic arthritis develop arthritis mutilans — a severe, painful, and disabling form of the disease. Over time, arthritis mutilans destroys the small bones in the hands, especially the fingers, leading to permanent deformity and disability.

People who have psoriatic arthritis sometimes also develop eye problems such as pinkeye (conjunctivitis) or uveitis, which can cause painful, reddened eyes and blurred vision. They are also at higher risk of cardiovascular disease.