Psoriatic arthritis is a form of arthritis that can affect people who have psoriasis. It is characterised by swelling, pain and stiffness in the joints. Approximately one in five people who have psoriasis will be affected by psoriatic arthritis. Psoriasis is a condition that affects the skin, causing red patches and flaking. It can also affect the immune system, which is why it can develop into arthritis if the immune cells begin to attack the body's own tissues. The arthritis usually appears within ten years of being diagnosed with psoriasis. It often begins in middle age, but it can affect people with psoriasis at any time.
The main symptoms of psoriatic arthritis are swelling, stiffness and tenderness or pain in the joints. These symptoms tend to come and go in unpredictable flare-ups, so the severity can vary significantly over time. Psoriatic arthritis most often affects the joints in the hands and feet. When the fingers are affected, they can become so swollen that they appear sausage-like. This condition is known as dactylitis.
The tendons and ligaments that attach bones and muscles together can also become swollen, making it painful and difficult to move the affected joints. If you start to develop any of these symptoms in your joints, or if you are experiencing back pain, you should visit your doctor to find out whether you might be suffering from arthritis.
You should be particularly aware of these kinds of symptoms if you have already been diagnosed with psoriasis, since you are at risk of developing psoriatic arthritis, but you may also need to consult a doctor even if you do not have psoriasis. Even if you don't have psoriatic arthritis, you might still be experiencing a different form of arthritis.
You will probably need to see a rheumatologist if your GP thinks you may have psoriatic arthritis, in order to confirm the diagnosis and start treatment. The rheumatologist will ask about your symptoms, examine your joints, and may also conduct some blood tests. These tests can reveal signs of inflammation and tell the doctor more about your condition.
Once the diagnosis has been confirmed, treatment can begin. It will probably involve medication in order to reduce the symptoms and slow the progress of the disease. Non-steroidal anti-inflammatory drugs (NSAIDs) are often used to relieve the pain of arthritis and reduce inflammation, but in some cases, steroid tablets or injections may be given instead.
However, when the arthritis is linked to psoriasis, rheumatologists need to be particularly careful about prescribing steroids, as a flare-up of the skin condition can be triggered when the steroid treatment is stopped. In addition to pain relief, other drugs may also be given to prevent the arthritis from getting worse.
Disease-modifying anti-rheumatic drugs (DMARDs) will usually be tried first, but biological treatments are available as an alternative. Lifestyle changes can also help patients cope with the symptoms, so rheumatologists will often work closely with physiotherapists and occupational therapists, as well as dermatologists, to provide the right treatment for psoriatic arthritis.