Psoriasis is a skin disease caused by the immune system attacking skin cells. One possible complication of psoriasis is psoriatic arthritis, a type of joint pain that occurs in some, but not all, cases of psoriasis. It is estimated by health organizations that approximately one out of every twenty people with psoriasis will have some symptoms of psoriatic arthritis.
The direct cause of the arthritis involved with psoriasis is not known, but there is a genetic tie with psoriasis. Psoriasis is an inherited disease that runs in families, but not all of the people who inherit the genes that contribute to the development of psoriasis will get the disease. Psoriasis is an autoimmune disease, and arthritis associated with psoriasis may be a direct complication of the misdirected immune response. There are other types of arthritis, such as rheumatoid arthritis, that are also caused by an inappropriate immune response.
Psoriasis symptoms and psoriatic arthritis symptoms tend to wax and wane; the symptoms are worse during an outbreak of psoriasis. Psoriatic arthritis can affect one or more joints, unilaterally or bilaterally. That is, the joints affected can be few or many, on one side or on both sides of the body. Arthritis literally means inflammation of the joints. Joint inflammation causes joint swelling, joint stiffness and joint pain. In addition to joint swelling, pain and stiffness, psoriatic arthritis can also cause swelling of the fingers and deformities of the joints, pain in the achilles tendon of the foot or plantar fascia at the bottom of the foot and pain in the lower back.
Like rheumatoid arthritis, psoriatic arthritis can lead to worsening joint degeneration and deformity if the condition is left untreated. Psoriatic arthritis symptoms can be mild or severe. The most severe form of the condition is called “arthritis mutilans,” and it involves severe joint pain and the gradual destruction of certain smaller bones in the hands.
People with symptoms of psoriatic arthritis may need to undergo tests to determine the cause of the arthritis. Most people with psoriatic arthritis also clearly suffer from skin symptoms of psoriasis, making the cause of the condition clinically obvious. However, in rare cases a person may suffer from arthritis symptoms before noticeable skin symptoms occur or a person with psoriasis may also have a different type of arthritis by coincidence. Diagnostic tests can help distinguish different types of arthritis. Rheumatoid arthritis and psoriatic arthritis can usually be told apart by doing a rheumatoid factor test; usually, a person with rheumatoid arthritis will have a type of antibody called rheumatoid factor in their blood, while a person with psoriatic arthritis will not. Gout, another major cause of arthritis, can be distinguished because it causes high levels of uric acid in the joint fluid. X-rays and MRIs can also distinguish between psoriatic arthritis and other types of arthritis.
Neither psoriasis nor psoriatic arthritis can be cured, but there are treatments that can help manage the conditions. Psoriatic arthritis can be treated using non-steroidal anti-inflammatory drugs (NSAIDs) to reduce joint inflammation, pain and swelling. NSAIDs may be prescribed or purchased over the counter. Long-term use of NSAIDs can be dangerous, however, due to the risk of side effects such as gastrointestinal bleeding. In addition, too much NSAID use can also make the skin symptoms of psoriasis worse instead of better.
A group of drugs called disease-modifying anti-rheumatic drugs can be used to treat types of arthritis caused by autoimmune diseases, such as rheumatoid arthritis and psoriatic arthritis. It takes a while for these medications, sometimes called DMARDs, to start working. However, these drugs can reduce the amount of damage that the immune system causes to the joints, decreasing deformity of joints and disability. Methotrexate is a common DMARD that is used to treat rheumatoid arthritis and psoriatic arthritis.
The most potent but most dangerous treatment for psoriatic arthritis is the use of immunosuppressant drugs. These drugs can counteract the effects of an autoimmune disease, but they put a person more at risk for developing infections, anemias and certain types of cancer. This type of treatment is generally reserved for the worst cases of autoimmune diseases. Some immunosuppressant drugs include cyclosporine and azathioprine. A class of drugs called TNF-alpha inhibitors can also control psoriatic arthritis by interfering with the immune response, but these drugs also have a lot of potential side effects.
Lifestyle changes can be made to help with psoriatic arthritis symptoms. Examples include weight loss if you are overweight, low-impact exercises to keep joints flexible, use of ice packs or heating pads and frequently resting your joints. The key is to remain active, but not to place too much stress on the joints, as this can increase pain and swelling. Weight loss decreases the amount of pressure on joints, especially in the lower limbs, and has other health benefits as well. Ice and heating pads can help soothe pain and reduce joint swelling.