Psoriatic arthritis is a type of arthritic inflammation that occurs in about 15 percent of patients who have a skin rash called psoriasis. This particular arthritis can affect any joint in the body, and symptoms vary from person to person. Research has shown that persistent inflammation from psoriatic arthritis can lead to joint damage. Fortunately, available treatments are effective for most people.
- Early diagnosis is important to avoid damage to joints.
- Psoriatic arthritis can occur in people without skin psoriasis, particularly in those who have relatives with psoriasis.
- Physical activity helps maintain joint movement.
What is psoriatic arthritis?
Psoriasis is a disease in which scaly red and white patches develop on the skin. Psoriasis is caused by the body’s immune system going into overdrive to attack the skin. Some people with psoriasis can also develop psoriatic arthritis, when the immune system attacks the joints as well, causing inflammation. Like psoriasis, psoriatic arthritis symptoms flare and subside, vary from person to person, and even change locations in the same person over time.
Psoriatic arthritis can affect any joint in the body, and it may affect just one joint, several joints or multiple joints. For example, it may affect one or both knees. Affected fingers and toes can resemble swollen sausages, a condition often referred to as dactylitis. Finger and toe nails also may be affected.
Psoriatic arthritis in the spine, called spondylitis, causes pain in the back or neck, and difficulty bending. Psoriatic arthritis also can cause tender spots where tendons and ligaments join onto bones. This condition, called enthesitis, can result in pain at the back of the heel, the sole of the foot, around the elbows or in other areas. Enthesitis is one of the characteristic features of psoriatic arthritis.
Recent research suggests that persistent inflammation from psoriatic arthritis causes joint damage later, so early accurate diagnosis is essential. Fortunately, treatments are available and effective for most people.
What causes psoriatic arthritis?
What causes psoriatic arthritis is not known exactly. Of those with psoriatic arthritis, 40 percent have a family member with psoriasis or arthritis, suggesting heredity may play a role.
Psoriatic arthritis can also result from an infection that activates the immune system. While psoriasis itself is not infectious, it might be triggered by a streptococcal throat infection.
Who gets psoriatic arthritis?
Psoriatic arthritis usually appears in people between the ages of 30 to 50, but can begin as early as childhood. Men and women are equally at risk. Children with psoriatic arthritis are also at risk to develop uveitis (inflammation of the middle layer of the eye).
Approximately 15 percent of people with psoriasis develop psoriatic arthritis. At times, the arthritis can appear before the skin disorder.
How is psoriatic arthritis diagnosed?
To diagnose psoriatic arthritis, rheumatologists look for swollen and painful joints, certain patterns of arthritis, and skin and nail changes typical of psoriasis. X-rays often are taken to look for joint damage. MRI, ultrasound or CT scans can be used to look at the joints in more detail.
Blood tests may be done to rule out other types of arthritis that have similar signs and symptoms, including gout, osteoarthritis and rheumatoid arthritis. In patients with psoriatic arthritis, blood tests may reveal high levels of inflammation and mild anemia. Occasionally skin biopsies (small samples of skin removed for analysis) are needed to confirm the psoriasis.
How is psoriatic arthritis treated?
Treatment varies depending on the level of pain. Those with very mild arthritis may require treatment only when their joints are painful and may stop therapy when they feel better.
Non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin or Advil) or naproxen (Aleve) are used as initial treatment.
If the arthritis does not respond, disease modifying anti-rheumatic drugs may be prescribed. These include sulfasalazine (Azulfidine), methotrexate (Rheumatrex), cyclosporine (Neoral, Sandimmune) and leflunomide (Arava). Sometimes combinations of these drugs may be used together. The anti-malarial drug hydroxychloroquine (Plaquenil) can help, but it usually is avoided as it can cause a flare of psoriasis. Azathioprine (Imuran) may help those with severe forms of psoriatic arthritis.
The more recently available anti-tumor necrosis factor agents such as adalimumab (Humira), etanercept (Enbrel), golimumab (Simponi) and infliximab (Remicade) are also available and can help the arthritis as well as the skin psoriasis.
For swollen joints, corticosteroid injections can be useful. Surgery can be helpful to repair or replace badly damaged joints.
Broader health impact of psoriatic arthritis
The impact of psoriatic arthritis depends on the joints involved and the severity of symptoms. Fatigue and anemia are common. Some psoriatic arthritis patients also experience mood changes. Treating the arthritis and reducing the levels of inflammation helps with these problems.
People with psoriasis are slightly more likely to develop high blood pressure, high cholesterol, obesity or diabetes. Maintaining a healthy weight and treating high blood pressure and cholesterol are also important aspects of treatment.
Living with psoriatic arthritis
Many people with arthritis develop stiff joints and muscle weakness due to lack of use. Proper exercise is very important to improve overall health and keep joints flexible. This can be quite simple.
Walking is an excellent way to get exercise. A walking aid or shoe inserts will help to avoid undue stress on feet, ankles, or knees affected by arthritis. An exercise bike provides another good option, as well as yoga and stretching exercises to help with relaxation.
Some people with arthritis find it easier to move in water. If this is the case, swimming or walking laps in the pool offers activity without stressing joints.
Many people with psoriatic arthritis also benefit from physical and occupational therapy to strengthen muscles, protect joints from further damage, and increase flexibility.
Points to remember
- Psoriatic arthritis is a chronic arthritis. In some people, it is mild, with just occasional flare ups. In other people, it is continuous and can cause joint damage if it is not treated.
- For most people, appropriate treatments will relieve pain, protect the joints, and maintain mobility.
- Psoriatic arthritis is sometimes misdiagnosed as gout, rheumatoid arthritis or osteoarthritis.
The rheumatologist’s role in the treatment of psoriatic arthritis
Psoriatic arthritis is easy to confuse with other diseases. As specialists in musculoskeletal disorders, rheumatologists are more likely to make a proper diagnosis. They also can advise patients about the best treatment options.
For more information
The American College of Rheumatology has compiled this list to give you a starting point for your own additional research. The ACR does not endorse or maintain these Websites, and is not responsible for any information or claims provided on them. It is always best to talk with your rheumatologist for more information and before making any decisions about your care.
The Arthritis Foundation
The Psoriasis Foundation
National Institute of Arthritis and Musculoskeletal and Skin Diseases
Updated September 2012
Written by Paul Emery, MD, and Zoe Ash, MD, and reviewed by the American College of Rheumatology Communications and Marketing Committee.
This patient fact sheet is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.
©2012 American College of Rheumatology