Psoriatic Arthritis

Psoriatic Arthritis Overview

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October 2014

What Is Psoriatic Arthritis?

Psoriatic arthritis is a form of arthritis (joint inflammation) that can occur in people who have the skin disease psoriasis. Psoriasis is a common condition characterized by scaly red and white skin patches. Psoriatic arthritis can affect any joint in the body, including the spine.

Who Is Affected?

Anyone can be affected by psoriatic arthritis, but it is more common in Caucasians than African Americans or Asian Americans. It most commonly appears between the ages of 30 and 50, but it can also begin in childhood. According to the Centers for Disease Control and Prevention (CDC), 10 to 20 percent of people with psoriasis eventually develop psoriatic arthritis. Typically, skin disease precedes the arthritis, sometimes by several years. However, in some cases, arthritic symptoms appear first.

What Is the Cause?

The cause of psoriatic arthritis is not known; however, doctors believe a combination of genetic and environmental factors is involved. Research shows that people with psoriatic arthritis often have a family member with psoriasis or arthritis. In people who are susceptible, an infection may activate the immune system, triggering the development of psoriatic arthritis.

What Are the Symptoms?

Psoriatic arthritis affects both the skin and the musculoskeletal system. The joints most commonly affected are the distal joints (those closest to the nail) of the fingers or toes, as well as the wrists, knees, ankles, and lower back.

Symptoms of Psoriatic Arthritis

Musculoskeletal symptoms may include:

  • Joint pain and swelling that may come and go and may be accompanied by redness and warmth.
  • Tenderness where muscles or ligaments attach to the bones, particularly the heel and bottom of the foot.
  • Inflammation of the spinal column, called spondylitis, which can cause pain and stiffness in the neck and lower back.
  • Morning stiffness.
  • Reduced range of motion of the joints.
  • Painful, sausage-like swelling of the fingers and/or toes.

Skin symptoms may include:

  • Thickness and reddening of the skin with flaky, silverwhite patches, called scales.
  • Pitting of the nails or separation from the nail bed.

Other symptoms may include:

  • General fatigue and malaise.
  • Conjunctivitis (also known as pink eye), inflammation, or infection of the membrane lining the eyelid and part of the eyeball.

How Is Psoriatic Arthritis Diagnosed?

The diagnosis of psoriatic arthritis is made based on the findings of a medical and family history and physical exam as well as x rays or magnetic resonance imaging (MRI) of the affected joints. Although there is no lab test to diagnose psoriatic arthritis, your doctor may order tests on blood or joint fluid to rule out other forms of arthritis with similar symptoms. If you have psoriasis and start to develop joint pain, its important to see your doctor. Early diagnosis and treatment of psoriatic arthritis can help prevent irreparable joint damage.

How Is Psoriatic Arthritis Treated?

Treatment for psoriatic arthritis will depend largely on its severity. If the disease is mild and affects only a couple of joints, treatment with nonsteroidal antiinflammatory drugs (NSAIDs)1 may be sufficient for treating pain and inflammation. For acutely inflamed joints, corticosteroid injections may be helpful. For more persistent disease affecting multiple joints, stronger disease-modifying antirheumatic drugs (DMARDs) and/or antitumor necrosis factor (TNF) agents may be needed to control the disease.2


1 Warning: Side effects of NSAIDs include stomach problems; skin rashes; high blood pressure; fluid retention; and liver, kidney, and heart problems. The longer a person uses NSAIDs, the more likely he or she is to have side effects, ranging from mild to serious. Many other drugs cannot be taken when a patient is being treated with NSAIDs, because NSAIDs alter the way the body uses or eliminates these other drugs. Check with your health care provider or pharmacist before you take NSAIDs. NSAIDs should only be used at the lowest dose possible for the shortest time needed.

2 All medicines can have side effects. Some medicines and side effects are mentioned in this publication. Some side effects may be more severe than others. You should review the package insert that comes with your medicine and ask your health care provider or pharmacist if you have any questions about the possible side effects.

What Research Is Being Done?

Researchers throughout the United States and the world are conducting research that will eventually improve the understanding and outcomes of psoriatic arthritis.

Some promising areas of research include:

Genetics. Scientists supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) are working to uncover genes associated with psoriasis, as well as modifier genes that can indicate which people with psoriasis are also at risk for psoriatic arthritis. Identification of genes that increase the risk of psoriatic arthritis will help scientists unlock the secrets of this troubling disease, and identify targets for more specific and effective therapy.

Biologic therapies. Biologic therapies that block the inflammatory cytokine TNF have proven to be among the most effective therapies for psoriatic arthritis. A number of other biologic agents are currently in clinical trials for psoriatic arthritis, and researchers continue to look for targets of biologic therapy for the disease.

Role of vitamin D. A recent study showed that vitamin D insufficiency is common in people with psoriatic arthritis. A new study supported by the NIAMS is designed to investigate the effects of vitamin D supplementation, along with marine omega-3 fatty acid and docosahexaenoic acid (DHA), on incidence, inflammation, and chronic pain in autoimmune diseases including psoriatic arthritis.

Risk factors. To better understand what causes psoriatic arthritis, with the eventual goal of stopping its development, scientists are looking into factors that predict risk of arthritis among people with psoriasis. One recent study found that people with psoriasis who reported being obese at age 18 were more likely to develop arthritis and develop it at an earlier age than people with a normal body mass index (BMI). Other research has shown that more severe skin disease is predictive of an increased risk of joint disease.

Diagnostics. The similarity between psoriatic arthritis and other inflammatory forms of arthritis can delay an accurate diagnosis, particularly when the arthritis precedes the skin disease. One group of researchers looking for better ways to diagnose the disease has found that a technique called contrast-enhanced MRI may help doctors differentiate between rheumatoid arthritis and psoriatic arthritis in the hand and wrist, which would enable them to target therapies to each condition.

Resources

American College of Rheumatology

Website: www.rheumatology.org

Arthritis Foundation

Website: www.arthritis.org

National Psoriasis Foundation

Website: www.psoriasis.org

# # #

The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH), is to support research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. The NIAMS information clearinghouse is a public service sponsored by the NIAMS that provides health information and information sources. Additional information can be found on the NIAMS website at www.niams.nih.gov.

The National Institutes of Health (NIH)—The Nation’s Medical Research Agency—includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary Federal agency for conducting and supporting basic, clinical, and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

For Your Information

This publication contains information about medications used to treat the health condition discussed here. When this publication was developed, we included the most up-to-date (accurate) information available. Occasionally, new information on medication is released.

For updates and for any questions about any medications you are taking, please contact

U.S. Food and Drug Administration

Toll free: 888-INFO-FDA (888-463-6332)
Website: http://www.fda.gov

For additional information on specific medications, visit Drugs@FDA at http://www.accessdata.fda.gov/scripts/cder/drugsatfda. Drugs@FDA is a searchable catalog of FDA-approved drug products.

For updates and questions about statistics, please contact

Centers for Disease Control and Prevention, National Center for Health Statistics

Website: http://www.cdc.gov/nchs

This publication is not copyrighted. Readers are encouraged to duplicate and distribute as many copies as needed.

Additional copies of this publication are available from:

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
National Institutes of Health

1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484
Toll free: 877-22-NIAMS (877-226-4267)
TTY: 301-565-2966
Fax: 301-718-6366
Email: NIAMSinfo@mail.nih.gov
Website: https://www.niams.nih.gov

If you need more information about available resources in your language or another language, please visit our website or contact the NIAMS Information Clearinghouse at NIAMSinfo@mail.nih.gov.

NIH Publication No. 14–AR-8001

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