What is psoriatic arthritis?
Psoriatic arthritis is a form of arthritis affecting the joints in around one in five people with the skin condition psoriasis.
Psoriatic arthritis often affects the hands and feet, causing swelling, stiffness, pain and problems moving the joints.
Once it develops, psoriatic arthritis is a long-term condition. Psoriatic arthritis can affect people of all ages, but is most common among middle-aged adults.
Types of psoriatic arthritis
Just like the symptoms of psoriasis, the pain and swelling of psoriatic arthritis are caused by an overactive immune system, which inflames the tissues around the joint. Typically, symptoms will flare-up and recede periodically.
There are five different kinds of psoriatic arthritis.
- Asymmetric arthritis makes up about 70% of all cases of psoriatic arthritis. It often involves one or a few joints, like the knee, hip or fingers. Although it's frequently mild, it can sometimes be debilitating. The inflamed joints may be red and hands and feet may be swollen.
- Symmetric arthritis is the second most common form of psoriatic arthritis. It often causes symptoms in the same joints on both sides of the body. Symptoms are similar to rheumatoid arthritis and symmetric arthritis can cause permanent damage.
- Distal interphalangeal predominant (DIP), a less common form of psoriatic arthritis, affects the joints close to the fingernails and toenails. The nails are often affected too.
- Spondylitis can make movement painful, especially in the neck and back. It can also cause inflammation of the spinal column.
- Arthritis mutilans is a rare and often debilitating and destructive form of psoriatic arthritis. It often affects the hands and feet, and sometimes the back and neck, and it can result in permanent deformity.
Symptoms of psoriatic arthritis
The symptoms of psoriatic arthritis are similar to those of other kinds of arthritis. They include:
- Stiffness in the joints
- Pain or swelling in the joints
How is psoriatic arthritis diagnosed?
In order to identify psoriatic arthritis, your GP will perform a physical examination. Your GP may also arrange blood tests, joint fluid tests and X-rays in order to examine the affected areas and rule out other diseases.
Of course, the usual symptoms of psoriasis, such as red, scaly patches of skin, may make diagnosis of psoriatic arthritis easier.
If your doctor suspects you have psoriatic arthritis you may be referred to an arthritis specialist or rheumatologist.
Treatments for psoriatic arthritis
While some of the treatments for psoriasis will also help psoriatic arthritis, others will not. If you have psoriatic arthritis, you should be getting a treatment that works on both the joint pain and the skin lesions caused by the condition. Some common treatments include:
- Nonsteroidal anti-inflammatory drugs ( NSAIDs). These are a common class of painkillers that are typically the first choice for treating psoriatic arthritis. They include a number of over-the-counter medications such as aspirin and ibuprofen . Many others are available by prescription. Although you may think of these painkillers as harmless, you should talk to your GP before using them to treat your arthritis. Chronic usage can be dangerous and cause gastrointestinal problems.
- Disease modifying antirheumatic drugs (DMARDs). The DMARDs are more powerful drugs that are used for cases of psoriatic arthritis that don't respond to less powerful medications. Some of the drugs used include methotrexate and sulfasalazine. Both are powerful drugs that help fight psoriasis by suppressing the immune system. They may also cause serious side effects and increase the risk of infection.
- Oral steroids. Your doctor may also recommend a short prescription of oral steroids to help treat acute joint pain, although steroids cannot usually be used safely for long periods of time. Stopping treatment with steroids suddenly can also cause a flare-up of symptoms.
- Biological therapy. The newest tools for treating psoriasis and psoriatic arthritis are biological drugs called anti-TNF or TNF inhibitors and include etanercept, infliximab, and adalimumab. These work by targeting the immune system response that causes the symptoms of psoriasis, preventing the joints from becoming inflamed. Biological drugs may also make the immune system more susceptible to infections.
- Other treatments. Guided physiotherapy, which can improve strength and flexibility, is often helpful for people with psoriatic arthritis. Using hot and cold packs can also make a difference because cold can numb pain and heat can relax muscles. You should also try to eat a balanced diet high in fruit and vegetables, maintain a healthy weight and take regular exercise, if possible. Do what you can to reduce stress, perhaps by practising relaxation techniques.
- Assistive devices. If your arthritis is making it difficult for you to do everyday things, buttoning your shirt, opening a bottle, or getting up from a chair, ask you GP about assistive devices, tools or gadgets that make common tasks easier for people with debilitating arthritis.