Psoriatic arthritis is an inflammatory joint disease associated with psoriasis. Like all arthritis, psoriatic arthritis can cause stiffness, pain and reduced movement in affected areas. It most commonly affects the joints in the hands and feet, but can also cause inflammation, swelling and pain in larger joints, including the knees, elbows, hips and the spine. The inflammation in psoriatic arthritis can also affect the tendons (the fibrous tissue that attaches the muscle to the bone), known as enthesitis.
WHAT ARE THE SYMPTOMS?
Symptoms of psoriatic arthritis range from mild to severe and can wax and wane in a similar way to skin psoriasis. Psoriatic arthritis usually affects the joints that are closest to the nail (distal joints) in both the fingers and the toes. The lower back, wrists, knees and ankles, alongside the neck, shoulders and elbows may also be affected. Some people may also experience rashes and fatigue.
WHO IS AFFECTED?
Psoriasis is a common skin condition affecting 2-3% of the population of the UK and Ireland. An estimated 5-7% of people with psoriasis have psoriatic arthritis. This figure can increase to approximately 40% in people who have severe psoriasis. Men and women are equally likely to develop psoriatic arthritis with the peak onset being between the ages of 30 and 50 years (however psoriatic arthritis can occur at any age).
In most cases (70%) psoriasis precedes psoriatic arthritis, in 15% of cases the skin and joint conditions occur at the same time and in the remaining 15% psoriatic arthritis is present before the skin condition psoriasis appears.
WHY DOES IT HAPPEN?
The cause of psoriatic arthritis is unknown. However, having a parent with psoriasis increases your risk of developing PsA. Some people have also developed PsA after an infection, such as a streptococcus throat.
HAVE I GOT PSORIATIC ARTHRITIS?
There is no specific test for psoriatic arthritis. Diagnosis is made by looking for a history of psoriasis in you or your family, together with arthritis and inflammation in at least one joint. The pattern of the disease is also assessed to see if your symptoms fall into one of the subsets of psoriatic arthritis.
- red, scaly (silvery), thick, itchy, flaking, sore or bleeding patches on your skin, anywhere on your body?
- are any of your joints painful, swollen, stiff, or hot to touch, especially your hands, fingers, feet, toes, lower back or heel?
- increased general tiredness or fatigue
- a close relative who has been diagnosed with psoriasis
Having any of the symptoms above does not necessarily mean you have psoriatic arthritis. If you have any concerns and believe you have psoriatic arthritis, it may be appropriate to discuss these with your GP.