Psoriatic Arthritis

Overview, Causes, & Risk Factors

Psoriatic arthritis is a chronic inflammation of the joints that occurs in some people with a chronic skin and nail condition known as psoriasis. Psoriasis causes flare-ups of raised patches of skin covered with silvery scales. The onset of psoriasis may occur at any age but is most commonly seen between the ages of 15 and 50 years. Psoriatic arthritis can be noted before or after the skin lesions appear.

What is going on in the body?

People with psoriasis may develop arthritis that causes destruction of various joints. The lining of the joint, the synovium, becomes inflamed. It reacts by producing extra synovial fluid, resulting in a swollen joint. The smooth white surface of the joint, the hyaline cartilage, can become thin, worn, and rough.

What are the causes and risks of the disease?

Psoriatic arthritis occurs only in people with underlying psoriasis. Psoriasis occurs more often in people of European ancestry. Approximately 5% to 8% of people with psoriasis will develop this form of arthritis. It affects men and women equally.

While the exact cause of psoriatic arthritis is unknown, several factors are suspected to be triggers for the disease. These factors include the following:

environment

the person's immune system

genetics

Both psoriasis and psoriatic arthritis flare up in people with HIV, the immunodeficiency disorder associated with AIDS.

Symptoms & Signs

What are the signs and symptoms of the disease?

Following are some of the signs and symptoms of psoriatic arthritis:

skin lesions of psoriasis, which are red patches

swelling that gives a sausage-like appearance to the fingers and toes

joint swelling

deformed joints

joint pain

nail changes

fever

fatigue

eye irritation and redness

There are 5 main types of psoriatic arthritis. The most common type affects the small joints of the fingers and toes. Joints of the arms and legs, as well as bones of the spine, may also be affected by psoriatic arthritis.

Diagnosis & Tests

How is the disease diagnosed?

The diagnosis is made by identifying the typical symptoms of arthritis in a person with psoriasis. Blood tests, including a complete blood count, or CBC, may be done to rule out other diseases such as rheumatoid arthritis or gout. Joint X-rays may show severe erosion of joints.

In some people, the degree of skin psoriasis may be minimal. Careful examination is required to detect even small areas of psoriasis.

Prevention & Expectations

What can be done to prevent the disease?

There is no known way to prevent the development of psoriatic arthritis in someone who is prone to it.

What are the long-term effects of the disease?

Individuals who have psoriatic arthritis may have progressive destruction of the affected joints. This can lead to disfigurement and disability. Approximately 20% of people with psoriatic arthritis will have a severe course of disease.

What are the risks to others?

Psoriatic arthritis is not contagious and poses no risk to others.

Treatment & Monitoring

What are the treatments for the disease?

Much of the joint damage may appear in the beginning stages of the disease. For this reason, early treatment of psoriatic arthritis may be critical.

Following are medications used to treat psoriatic arthritis:

immunosuppressant medications, which alter the body's immune response. Methotrexate, a medication also used as cancer chemotherapy, is commonly used to treat psoriatic arthritis. Other immunosuppressant medications include azathioprine and cyclophosphamide.

anti-inflammatory medications, such as aspirin, naproxen, or ibuprofen

COX-2 specific inhibitor NSAIDs, such as celecoxib and rofecoxib

corticosteroids, such as prednisone, which are taken orally or by injection into the joint

antibiotics, such as doxycycline and minocycline

disease-modifiying medications, such as sulfasalazine and hydroxychloroquine. These medications help to slow down the joint destruction associated with the disease.

Other treatments for psoriatic arthritis may include:

education about the course of the disease and methods to preserve joint function

physical therapy to help maintain joint strength and range of motion

occupational therapy to learn energy conservation techniques

reduction of stress

splints to rest acutely inflamed joints

assistive devices, such as zipper pulls, to decrease strain on joints

healthy diet following the food guide pyramid, with adequate calories, protein, and calcium

Exercise is important in the treatment of arthritis. Thirty minutes of moderate exercise a day can help to prevent complications of arthritis, as well as heart disease, stroke, and diabetes. A person exercising at a moderate level can talk normally without shortness of breath and is comfortable with the pace of the activity. The 30 minutes a day can be done in one session, or it can be broken up into smaller segments. Low impact aerobics and water aerobics are examples of exercises that minimize joint stress.

Surgery may be performed when pain cannot be controlled or function is lost. Common procedures include the following:

arthroscopy, a procedure that uses a small scope and instruments to get inside the joint without opening it

arthrotomy, which involves opening the joint through a larger incision

synovectomy, which is the removal of the lining of the joint

osteotomy, which refers to the realignment of the bone next to the joint

arthroplasty, which is the partial or total replacement of the joint. Individuals with severe arthritis are often candidates for a knee joint replacement or a hip joint replacement.

There has been a great deal of interest lately in the use of glucosamine and chondroitin, dietary supplements that may decrease joint pain associated with arthritis. A large scale study is currently being conducted by the National Center for Complementary and Alternative Medicine and the National Institute of Arthritis and Musculoskeletal Disease to determine the effectiveness of these supplements.

What are the side effects of the treatments?

Medications used to treat psoriatic arthritis may cause stomach upset, allergic reaction, decreased resistance to infection, and other side effects. Surgery may cause bleeding, infection, or allergic reaction to anesthesia. Nearby bones, ligaments, tendons, nerves, or blood vessels can also be accidentally injured.

What happens after treatment for the disease?

Treatment of rheumatoid arthritis is lifelong. There is no cure for the disease, but careful management can help to minimize some of its effects. Periodic flare-ups of the disease are common.

How is the disease monitored?

A healthcare provider will monitor the person's level of comfort and function of the joint. Any new or worsening symptoms should be reported to the healthcare provider.