Psoriatic arthritis is a type of inflammatory arthritis that occurs in some patients with 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 for are effective for most people.
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% of people with psoriasis develop psoriatic arthritis. At times, the arthritis can appear before the skin disorder.
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, manifested by painful, stiff and swollen joints. 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 stiffness 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 is not known exactly. Of those with psoriatic arthritis, 40% 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, commonly known as strep throat.
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 but labs may also be normal. Anemia is a condition that occurs when the body lacks red blood cells or has dysfunctional red blood cells. Occasionally skin biopsies (small samples of skin removed for analysis) are needed to confirm the psoriasis.
Treating psoriatic arthritis varies depending on the level of pain, swelling and stiffness. 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, Trexall, Otrexup, Rasuvo), cyclosporine (Neoral, Sandimmune, Gengraf), and leflunomide. 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.
There are several biologic type medications available to treat psoriatic arthritis via infusion or injection.
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.
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.
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.
Updated March 2019 by Paul Sukfa, MD and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information 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.