What is Psoriatic Arthritis

What is psoriatic arthritis?

Psoriatic arthritis is a form of joint inflammation affecting people with the skin condition, psoriasis. The condition usually causes swelling and pain in and around the joints, and a scaly rash on the skin. It is estimated that about one-third of people with psoriasis develop psoriatic arthritis.

What is its prevalence in Ireland?

Psoriatic arthritis is a less common form of arthritis. It affects both men and women in equal numbers, and usually between 20-50. Up to 30% of people with psoriasis may get psoriatic arthritis. Although psoriasis may start at any age, the arthritis component usually makes its appearance later – in the 20s, 30s and 40s. Commonly, psoriasis occurs first, but sometimes arthritis may occur first.

Causes of psoriatic arthritis

Although the exact cause of psoriatic arthritis is unknown, family history is thought to play a role in one-third of people.

Research suggests that an environmental factor might act as a trigger in people who are susceptible to this type of arthritis.


Psoriatic arthritis varies from individual in the pattern of disease and what joints are likely to be affected.

Psoriatic arthritis can affect the neck, shoulders, elbows, wrists, hand joints, base of spine, knees, ankles and all joints of the toes. Sometimes a single joint in the body is affected, for others many joints are affected. Some individuals have only mild symptoms, while others have quite severe and disabling symptoms.

The other common features of psoriatic arthritis include tendonitis (swelling of the tendons) and pain and swelling at points where tendons and ligaments attach to the bone.

How is psoriatic arthritis diagnosed?

There is no specific test for psoriatic arthritis. Your doctor will make a diagnosis based on your symptoms and a physical examination. As family history is important in this condition, your GP may ask about a history of psoriasis in a close relative. They will also check for inflammation and/or swelling in at least one joint.

To distinguish between rheumatoid arthritis and other forms of arthritis, the doctor will look at the pattern of arthritis and other symptoms. X-rays will be used to look for changes in the bone. Blood and joint fluid tests may be carried out to rule out other conditions such as rheumatoid arthritis, reactive arthritis or gout.

How is psoriatic arthritis treated?

Although there is no cure for psoriatic arthritis, there are many different things you can do to lesson your pain and maintain your movement and function. Your health professional will advise on these.