What Causes Psoriatic Arthritis (PsA)?
While the direct cause of PsA is unknown, here's what we do know: First, you may be more likely to experience PsA if it's part of your family's medical history. Second, PsA symptoms begin when your immune system attacks healthy cells in your body, for reasons we do not yet understand.
Normally, the immune system (the body's natural defense system) protects your body from bacteria, viruses, or other foreign agents. When you have PsA, your immune system incorrectly attacks the linings of the joints and skin. This causes uncontrolled inflammation—leading to the joint and skin symptoms usually experienced with PsA.
Who gets PsA?
- Approximately 15% of people with psoriasis can develop PsA
- PsA affects men and women equally
- The disease can appear at any age, but usually occurs in people between the ages of 30 and 50
In many patients, joint symptoms can develop before skin symptoms appear. A rheumatologist or a dermatologist can determine if your symptoms are due to PsA. Rheumatologists are physicians who focus on treating arthritis and other joint diseases, while dermatologists are physicians who specialize in treating skin conditions. If you receive a diagnosis of active PsA, your rheumatologist may prescribe REMICADE® as part of your treatment plan.
Symptoms and diagnosis
If you experience any of the following symptoms of PsA, talk to a rheumatologist (arthritis specialist) as soon as possible.
PsA usually affects the finger and toe joints, but you may also experience symptoms in the lower back and heels. Some other characteristics of PsA include:
- Dactylitis (dak'-ti-li'tis), or inflammation and swelling in the joints at the ends of fingers or toes
- Enthesitis (en'-the-si'-tis),or inflammation in the tendons or ligaments and can occur at the heel
In PsA, uncontrolled inflammation can lead to the body producing too many skin cells. When the body produces too many of these cells, you can also get skin lesions. These lesions are areas of red patches covered by red and white scaly skin. They can occur anywhere on the body.
PsA and RA
Because the symptoms of PsA may resemble those of rheumatoid arthritis (RA), doctors may first look for scaly skin lesions. Since there is no simple test for determining whether you may have RA versus PsA, your doctor may look for cell abnormalities by examining a skin sample under a microscope. Typically, skin symptoms of PsA will appear before the arthritis associated with PsA. Blood tests and x-ray or MRI studies may also help confirm a diagnosis.
Take a closer look at PsA
When you have psoriasis and PsA, you have a skin condition that is marked by a rapid buildup of dry, dead skin cells that form thick scales.
In psoriatic arthritis, underlying inflammation leads to overproduction of your skin cells:
PsA also affects your joints, causing lasting pain, stiffness, and swelling. Since PsA is a progressive disease, this often leads to loss of movement and joint damage, particularly if left untreated.
Joint with psoriatic arthritis:
While the skin symptoms of PsA may be easy to identify, you can't see the joint damage caused by PsA. Over time, this can severely limit your ability to move. That's why it's important to see a dermatologist or rheumatologist immediately if you think you may be experiencing symptoms that resemble active PsA. If you are diagnosed with active PsA, your doctor may prescribe REMICADE® to help relieve your skin and joint symptoms and help stop further joint damage.