Psoriatic Arthritis

What is psoriatic arthritis?

Psoriatic arthritis is a form of arthritis associated with psoriasis, a chronic skin and nail disease characterized by red, scaly rashes and thick, pitted fingernails. The disease is similar to rheumatoid arthritis in symptoms, characterized by joint inflammation. However, psoriatic arthritis tends to affect fewer joints than rheumatoid arthritis and does not produce the typical rheumatoid arthritis antibodies. The arthritis associated with psoriatic arthritis comes in five forms:

  • Arthritis that affects the small joints in the fingers and/or toes

  • Asymmetrical arthritis of the joints in the extremities

  • Symmetrical polyarthritis, a type of arthritis similar to rheumatoid arthritis

  • Arthritis mutilans, a rare type of arthritis that destroys and deforms joints

  • Psoriatic spondylitis, arthritis of the sacroiliac sac (in the lower back) and the spine

What causes psoriatic arthritis?

Although the cause of psoriatic arthritis is unknown, factors such as immunity, genetics, and the environment may play a role.

What are the symptoms of psoriatic arthritis?

The following are the most common symptoms of psoriatic arthritis. The skin condition, psoriasis, may actually precede or follow psoriatic arthritis. However, each individual may experience symptoms differently. Symptoms may include:

  • Inflamed, swollen, and painful joints, usually in the fingers and toes

  • Deformed joints from chronic inflammation

The symptoms of psoriatic arthritis may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.

How is psoriatic arthritis diagnosed?

When psoriasis has been diagnosed, a diagnosis of psoriatic arthritis may be easily confirmed. However, when psoriatic arthritis symptoms precede other symptoms of psoriasis, diagnosis is more difficult. Although psoriatic arthritis sometimes causes an increased erythrocyte sedimentation rate (ESR), mild anemia, and elevated blood uric acid levels, these symptoms are also associated with other rheumatic diseases, including gout. ESR is a measurement of how quickly red blood cells fall to the bottom of a test tube. When swelling and inflammation are present, the blood's proteins clump together and become heavier than normal. Thus, when measured, they fall and settle faster at the bottom of the test tube. Generally, the faster the blood cells fall, the more severe the inflammation.

Treatment for psoriatic arthritis

Specific treatment for psoriatic arthritis will be determined by your doctor based on:

  • Your age, overall health, and medical history

  • Extent of the condition

  • Your tolerance for specific medications, procedures, and therapies

  • Expectation for the course of the disease

  • Your opinion or preference

Treatment usually involves treating both the skin condition and the joint inflammation. Some medications used to treat rheumatoid arthritis are also used to treat psoriatic arthritis, including:

  • Nonsteroidal anti-inflammatory medications to relieve symptoms

  • Vitamins and minerals, such as calcium and vitamin D, to slow bone deformation

  • Immunosuppressive medications, such as methotrexate to suppress inflammation if NSAIDs are not effective 

  • Biologic medications, such as the drugs Enbrel (etanercept) and Humira (adalimumab) 

Other treatment may include:

  • Corticosteroids for inflammation

  • Ultraviolet light treatment (UVB or PUVA)

  • Heat and cold

  • Splints

  • Exercise

  • Physical therapy to improve and maintain muscle and joint function

  • Occupational therapy to improve ability to perform activities of daily living

  • Dermatology management of psoriasis skin rash, if present

  • Surgery to repair or replace a damaged joint; if warranted, this usually occurs years after the initial diagnosis