Psoriatic arthritis (PsA) is an inflammatory type of arthritis that can affect people who have psoriasis. Arthritis attacks the joints, causing them to become painful, swollen and often warm to the touch. Psoriasis produces red or silver scales or sore patches on the skin. Psoriasis results when the body's own immune system attacks the skin cells, causing them to be replaced at a faster than normal rate.
When the immune system attacks the joints in a person with psoriasis, the result is psoriatic arthritis. Both psoriasis and psoriatic arthritis are chronic conditions that get worse over time. About 15 percent of people with psoriasis will also develop psoriatic arthritis.
In most cases, the skin condition develops first, with the onset of psoriatic arthritis occurring at a later date. But in some cases, PsA may develop before the skin condition is diagnosed. Most people develop psoriatic arthritis between the ages of 30 and 50 years, but it can begin at any age.
PsA can affect any joint in the body. It may be mild and affect only a few joints or many or may be more serious and affect many joints. It can also affect just one side of the body or may occur on both sides.
PsA often affects the joints in the fingers and toes more than other joints. This can result in the appearance of sausage-like fingers due to swelling caused by joint inflammation.
PsA in the spine can cause pain in the neck or back as well as difficulty bending. PsA can also cause pain where tendons and ligaments attach to bones such as in the heel and in the sole of the foot.
Psoriatic arthritis can be diagnosed by observing swollen, painful joints, certain patterns of joint inflammation, and changes to the skin and nails associated with psoriasis.
X-rays can be used to verify joint inflammations while blood tests are used to rule out other conditions with similar symptoms such as rheumatoid arthritis, gout and osteoarthritis.
Psoriatic arthritis can cause severe damage to joints if left untreated. If you have psoriasis or if you are concerned that you might have psoriatic arthritis, talk to your health care provider.