Psoriatic arthritis is arthritis related to psoriasis. It is a type of inflammatory arthritis and a type of spondylitis. You may see it shortened to PsA in some places.
Psoriatic arthritis affects the joints, but it can also affect tendons, ligaments, and the places where ligaments and muscles attach to bones.
What is psoriasis?
Most people who have psoriatic arthritis have psoriasis, with psoriasis usually coming first. Psoriasis is a skin condition that usually shows up as dry, itchy, flaky skin. However, there are a few other types of psoriasis as well. Psoriasis can also affect the nails.
However, people can have psoriasis without having psoriatic arthritis. Up to 30% of people with psoriasis will develop psoriasis. And, though rare, you can also have psoriatic arthritis without having psoriasis.
- Usually surfaces between 20 and 50
- Is rare, affecting about 0.25% of the general population in Canada
- Can affect one joint at a time or multiple joints
- Goes through periods of worse symptoms (flares) and fewer symptoms – sometimes without any reason whatsoever