Psoriatic Arthritis Quiz: Test Your Medical IQ

Psoriatic arthritis is an inflammatory form of arthritis that can develop in people who have psoriasis, an autoimmune condition that causes raised, red, scaly patches on the skin due to the fast rate of skin cell growth and renewal. Psoriatic arthritis involves the skin and it affects the joints differently than other types of arthritis.

About 30% of patients with psoriasis will go on to develop psoriatic arthritis, and men and women are equally at risk for developing the condition. However, psoriatic arthritis may progress differently in men and women. Men may be more likely to develop joint damage, while women may experience more severe symptoms.

There does not appear to be a single cause of psoriatic arthritis, but it is believed to develop due to a combination of genetic, immunologic, and environmental factors. About 40% of people who have psoriatic arthritis have family members with psoriasis or psoriatic arthritis.

Common symptoms of psoriatic arthritis include joint pain and swelling sometimes accompanied by skin redness and warmth, reduced range of motion in the joints, scaly and itchy skin, and thickening skin. Other symptoms of psoriatic arthritis include pain and stiffness of the neck and lower back, sausage-like swelling of fingers and/or toes, abnormal skin thickness, nails separate from nail bed, fatigue, and pink eye (conjunctivitis) or other eye inflammation.

Psoriasis, an autoimmune disorder that affects the skin, usually appears before psoriatic arthritis. About 10-20% of people with psoriasis will develop psoriatic arthritis. Early diagnosis and treatment can help prevent joint damage.

A dermatologist or general practitioner would generally diagnose psoriasis, a skin condition. If psoriatic arthritis is suspected you will likely be referred to a rheumatologist, a specialist in diagnosis and treatment of arthritis and joint diseases for confirming a diagnosis and creating a treatment plan.

There are five types of psoriatic arthritis:

- Symmetric psoriatic arthritis affects joints on both sides of the body at the same time. It is similar to rheumatoid arthritis, and accounts for about half of all cases of PsA.
- Asymmetric psoriatic arthritis doesn't appear in the same joints on either side of the body. It accounts for about 35% of all cases of PsA and is often mild.
- Distal psoriatic arthritis causes inflammation and stiffness near the ends of the fingers and toes, and changes in toenails and fingernails.
- Spondylitis is pain and stiffness in the spine and neck.
- Arthritis mutilans affects only 5 percent of people with PsA, but is the most severe form of the disease. It causes severe deformities in the small joints at the ends of the fingers and toes.

Treatment for psoriatic arthritis depends on the severity of the disease and how many joints are affects. If the condition is mild, over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) may be used for pain and inflammation. More severe inflammation may require corticosteroid injections into the joints. In severe cases of the disease that affect multiple joints, medications such as disease-modifying anti-rheumatic drugs (DMARDs) or antitumor necrosis factor (TNF) agents may be prescribed.

About 80% of people with psoriatic arthritis have fingernail or toenail psoriasis. Nail changes can include pitted nails that separate from the nail bed, crumbling nails, ridges on the nails, nail discoloration, and spots of blood under the nail.