- Psoriatic arthritis is 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. Early diagnosis is important to avoid damage to joints.
- Psoriatic arthritis typically occurs in people with skin psoriasis, but it can occur in people without skin psoriasis, particularly in those who have relatives with psoriasis.
- Psoriatic arthritis typically affects the large joints, especially those of the lower extremities, small joints of the fingers and toes, and can affect the spine and sacroiliac joints of the pelvis. Eyes, tendons, gastrointestinal system, and nails can also be involved.
- For most people, appropriate treatments will relieve pain, protect the joints, and maintain mobility. Physical activity helps maintain joint movement.
Psoriatic arthritis is a type of inflammatory arthritis that can occur in some patients with psoriasis. This arthritis can affect several different joints in the body along with other organs such as the eyes and the GI system. Research has shown that persistent inflammation from psoriatic arthritis can lead to joint damage. Fortunately, available treatments are effective for most people and preserve mobility.
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 of developing uveitis (inflammation of the middle layer of the eye). Approximately 15% of people with psoriasis develop psoriatic arthritis. At times, arthritis can appear even before the skin disorder.
What Is Psoriatic Arthritis?
Psoriasis is an autoimmune condition in which the body’s immune system begins to target the cells of the skin, resulting in scaly red and white patches A small percentage of people with psoriasis can also develop psoriatic arthritis, also an autoimmune condition in which the immune system begins to cause inflammation in the joints resulting in painful, stiff, and swollen joints. Like psoriasis, psoriatic arthritis symptoms vary in severity from person to person.
Psoriatic arthritis can affect any joint in the body—it can affect just one joint or multiple joints. Affected fingers and toes can resemble sausages, a condition often referred to as dactylitis. Finger and toenails also may be affected and show nail pitting.
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?
What causes psoriatic arthritis is not known exactly. Of those with psoriatic arthritis, 40% have a family member with psoriasis or arthritis, suggesting genetics may play a role. While psoriasis itself is not infectious, it might be triggered by a streptococcal throat infection, commonly known as strep throat.
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, Lyme arthritis and rheumatoid arthritis. In patients with psoriatic arthritis, blood tests may reveal high levels of inflammation, but labs may also be normal. Occasionally skin biopsies (small samples of skin removed for analysis) are needed to confirm psoriasis.
How Is Psoriatic Arthritis Treated?
Treating psoriatic arthritis depends on the extent 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. Azathioprine (Imuran) may help those with severe forms of psoriatic arthritis.
Other treatments include biologics, typically starting with TNF inhibitors such as adalimumab (Humira), certolizumab pegol (Cimzia), etanercept (Enbrel), golimumab (Simponi), infliximab (Remicade). Other biologics used for psoriatic arthritis include the IL-17 inhibitors secukinumab (Cosentyx) and ixekizumab (Taltz), or other classes as ustekinumab (Stelara) and abatacept (Orencia). Newer oral medications, such as tofacitinib (Xeljanz) have also been shown to be effective.
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 such as depression. Treating arthritis and reducing the levels of inflammation help with these problems. People with psoriasis have an increased risk of high blood pressure, high cholesterol, obesity or diabetes. Maintaining a healthy weight and treating high blood pressure and cholesterol are 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 especially important to improve overall health and keep joints flexible. 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.
Aqua therapy can be beneficial as some people with arthritis find it easier to move in water. Many people with psoriatic arthritis also benefit from physical and occupational therapy to strengthen muscles, protect joints from further damage, and increase flexibility.
The Rheumatologist's Role in Treating 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.
Updated December 2021 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.