Psoriatic arthritis (PsA) is a form of inflammatory arthritis. It affects about 1 million people in the United States, or 30% of people who have psoriasis. Psoriasis is a skin disease that causes a red, scaly rash, most often on your elbows, knees, ankles, feet, and hands.
Psoriatic arthritis is an autoimmune condition. It happens when your body’s immune system attacks healthy tissue by mistake. PsA most often affects your skin and your joints, which can become swollen, stiff, and painful. Over time, if you don’t treat it, the inflammation can damage joints and tissues.
Scaly skin, especially on your knees, elbows, and scalpPsoriatic arthritis shares some symptoms with rheumatoid arthritis (RA). But RA usually affects joints on both sides of your body. It can also cause bumps under your skin. Other skin and nail changes are more likely with psoriatic arthritis.
Psoriatic Arthritis Treatment
Medical treatments for psoriatic arthritis include:
Disease-modifying antirheumatic drugs (DMARDs). These can slow or stop pain, swelling, and joint and tissue damage. If NSAIDs don’t work, your doctor will try DMARDs. They may take longer to work.
Immunosuppressants. If you can’t take a DMARD, you might get a type of drug called an immunosuppressant. These drugs curb your immune system, which is what’s causing the problem in an autoimmune condition like PsA. But they can also make it more likely that you’ll get an infection.
UV light. Therapy with UVA light can ease skin symptoms in people who have severe psoriasis. But it may also raise your chances of skin cancer.
Biologics. If immune suppression doesn't work, your doctor may prescribe a biologic. These are a newer type of DMARD. Rather than weaken your entire immune system, these medications block a protein that causes inflammation.
Enzyme inhibitor. This works by blocking a certain enzyme, a kind of protein, called PDE-4. That helps slow other reactions that lead to inflammation.
Steroids. These can help control inflammation, but doctors don’t use them often for PsA because they can make your skin rash worse. Doctors prescribe steroids only when you really need them. If you use them for a long time, you could have serious side effects such as brittle bones, weight gain, hypertension, and diabetes.
Surgery. A severely damaged joint can be replaced with a new one made from metal and plastic.
Psoriatic Arthritis Diagnosis
Your doctor will ask about your symptoms and whether any of your relatives have psoriasis, psoriatic arthritis, or another autoimmune disease. They’ll also check how well your joints move and whether you have pain, tenderness, swelling, or warmth. You may have tests including:
Imaging tests such as X-rays, MRIs, CT scans, and ultrasounds
Blood tests to rule out other kinds of arthritis and look for signs of inflammation
Tests of the fluid from your joints or tiny samples of skin