Doctor's Notes on Psoriatic Arthritis
Psoriatic arthritis is an autoimmune disease that usually affects the skin and joints. Signs and symptoms can range from none or minimal to severe. Minimal signs and symptoms may be just some scaly reddish skin on the scalp, navel or between the buttocks; others may have some abnormalities like lines going across nails, pits in the nails and yellow spots. Usually skin changes precede (sometimes by years) arthritic symptoms. Some patients develop eye problems (conjunctivitis, iritis). Over time, severe skin symptoms of large scaly patches develop, nails can be lost and arthritic changes in the joints can make the joints essentially unworkable (some joints may dissolve).
There are several types of psoriatic arthritis with somewhat different signs and symptoms:
- Asymmetrical oligoarticular arthritis – fingers and toes affected randomly with sausage shape appearance and usually less than five arthritic joints
- Symmetrical polyarthritis – arthritis involves similar sites like hands, wrists, feet and ankles on both sides of the body
- Arthritis mutilans – long term severely damaged joints especially in hands and feet
- Spondylitis – inflammation of the spinal vertebrae and possibly sacroiliac and hip joints
- Juvenile psoriatic arthritis – Occurs more often in 9-10-year-old girls, about 50% have only one joint affected but can have bone growth problems in the bone forming the joint.
The triggers for the autoimmune reaction that causes the disease are not known. Researchers speculate that a combination of genetic, environmental and immune factors interact. The inheritance tendency is the strongest risk factor.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.