Psoriatic arthritis (PsA) is a joint disease found in about 30% of patients with a skin condition called psoriasis. Psoriasis is an autoimmune disease, meaning it is caused by an overactive immune system. In this condition, the body’s immune system “attacks” healthy skin cells, which causes overgrowth of skin cells, causing inflammation, redness, burning, itching, and development of silvery scales and plaques on the skin. These plaques can occur anywhere on the skin, but most often are seen on the elbows, knees, and scalp. In psoriatic arthritis, patients with psoriasis experience pain, swelling, and stiffness in the joints, and areas around the joints, which can lead to severe joint damage. Most often, patients with PsA have been diagnosed with psoriasis for several years before developing psoriatic arthritis, but it is possible to have PsA before having any skin symptoms of psoriasis.
The symptoms of psoriatic arthritis include:
The skin condition, psoriasis, is a large risk factor for psoriatic arthritis, as nearly 1 in 3 patients with psoriasis develop PsA. Patients with a family history of PsA may have a genetic predisposition to developing the disease. Physical trauma/ injury or infection may trigger psoriatic arthritis in these patients.
Psoriatic arthritis cannot be diagnosed with a single test, but since it can be like other joint diseases, those will be ruled out to help confirm a PsA diagnosis. The doctor will examine the joints for swelling, redness, warmth, and tenderness, and will examine the nails for pitting or flaking. Blood tests will be used to rule out other autoimmune diseases, especially rheumatoid arthritis. Joint aspiration (drawing fluid out of a swollen joint with a needle) to check for uric acid crystals, which are present in gout, may be done. X-rays or other imaging tests are done to check for joint changes that may happen in PsA but not in other forms of arthritis.
There is no treatment that can cure psoriatic arthritis, but several medications are used to control symptoms of PsA and to prevent joint damage and disability, as well as to treat the skin-related symptoms associated with psoriasis. Other treatment options include physical therapy, exercise to keep joints from becoming too stiff, heat and cold treatment for symptom relief, joint injections, and in severe cases, surgery to replace heavily damaged joints.
The most common complication of psoriatic arthritis is joint damage and deformity. This can possibly make it difficult to use your joints to complete normal daily tasks such as housework, walking, or dressing yourself. A diagnosis of PsA can also make you at higher risk of developing other health conditions such as cancer, heart disease, inflammatory bowel disease, depression, vision problems due to eye inflammation, and diabetes. It is important to have regular visits with a rheumatologist (a doctor who specializes in immune-system disorders and related joint disease), and to take your medications as prescribed, as well as follow-up with a primary care provider to monitor for possible related health conditions. While it is not possible to prevent yourself from getting psoriatic arthritis, proper medication use can help to prevent complications. Maintaining a healthy weight can decrease stress on joints, and regular exercise can keep joints flexible and strengthen muscles, which helps protect the joints around them. Stopping smoking and limiting alcohol use can also help to prevent complications and increase effectiveness of treatment.