Psoriatic arthritis affects up to one in five people with psoriasis. This type of arthritis is unpredictable, but flare-ups can be usually be managed with treatment.
Like other types of arthritis, it means that one or more of your joints are inflamed and become swollen, stiff, painful, and difficult to move.
Read more about arthritis.
Psoriatic arthritis mostly affects your hands and feet, although any joint can be affected. The fingers can swell up and look like sausages – a condition known as dactylitis.
It can also make tendons and ligaments swollen and painful (tendons attach muscle to bone and ligaments attach bone to bone).
Who is affected?
Psoriatic arthritis is a long-term condition that can happen at any age, although it is most common in middle age.
It affects up to one in five people with psoriasis and usually develops within 10 years of psoriasis being diagnosed.
What to do
If you have been diagnosed with psoriasis and you have pain, swelling or stiffness in your joints, or you have back pain, see your GP as you might have psoriatic arthritis.
Your GP should refer you to a rheumatologist (a specialist in conditions of the joints) if you have psoriasis and:
- stiffness in one or more of your joints in the morning
- swelling or tenderness in some of your joints
- dactylitis (swelling of a finger or toe)
Your GP or specialist may carry out some blood tests to check for signs of inflammation and to check the levels of different types of cells in your blood.
Treating psoriatic arthritis
If you have psoriatic arthritis, you may be treated by a team of health professionals, including:
- a GP
- a rheumatologist
- a dermatologist (skin specialist)
- a nurse
- a physiotherapist
- an occupational therapist
- a psychologist (it's not unusual for people with arthritis to develop depression)
You may be given a number of different types of medicine for psoriatic arthritis, some of which can treat the psoriasis too. These are summarised below.
NSAID painkillers
Your GP may prescribe non-steroidal anti-inflammatory drugs (NSAIDs) to help relieve pain and stiffness, while also reducing inflammation.
There are two types of NSAIDs and they work in slightly different ways:
Read more about non-steroidal anti-inflammatory drugs (NSAIDs).
Steroid medication (corticosteroids)
Steroids help reduce pain, stiffness and swelling. They can be taken as a tablet (for example, prednisolone) or as an injection into the muscle, to help lots of joints. They are usually used when NSAIDs fail to provide relief.
However, doctors are generally cautious about giving steroid injections or tablets if the associated psoriasis is severe, as withdrawal of the steroids can cause the skin disease to flare up.
If you have a single inflamed or swollen joint, your doctor may inject the steroid directly into the joint. Relief is rapid and the effect can last from a few weeks to several months, depending on the severity of your condition.
Read more about corticosteroids.
Disease-modifying anti-rheumatic drugs (DMARDs)
DMARDs help to ease symptoms and slow the progression of psoriatic arthritis. When antibodies attack the tissue in the joints, they produce chemicals that can cause further damage to the bones, tendons, ligaments and cartilage. DMARDs work by blocking the effects of these chemicals. The earlier you start taking a DMARD, the more effective it will be.
Leflunomide is often the first drug given for psoriatic arthritis. Sulfasalazine or methotrexate may be considered as an alternative.
You can click on the above links for more information on these drugs, including the side effects.
It can take four to six months to notice a DMARD working. Therefore, it is important to keep taking the medication, even if it doesn't seem to be working at first.
Biological treatments
Biological drug treatments are a newer form of treatment for psoriatic arthritis. You may be offered treatment with a biological if:
- your psoriatic arthritis has not responded to at least two different types of DMARD
- you are not able to be treated with at least two different types of DMARD
Biological drugs work by stopping particular chemicals in the blood from activating your immune system to attack the lining of your joints.
Some of the biological medicines you may be offered are adalimumab, etanercept and infliximab injections. Read more about these drugs in the treatment of psoriasis.
Side effects from biological treatments are usually mild and include:
- skin reactions at the site of injection
- infections
- nausea
- fever
- headaches
Managing related conditions
If you have psoriatic arthritis, you may be more likely to get some other diseases, such as heart disease, diabetes and depression.
Your doctor should carry out tests each year (such as blood pressure and cholesterol tests) to check if you are developing these diseases.
In the meantime, you can help yourself by:
- having a good balance between rest and regular physical activity
- losing weight if you are overweight
- not smoking
- only drinking moderate amounts of alcohol
