Psoriatic arthritis usually strikes around age 30 to 50, equally affecting both men and women, but it may also start in childhood. The skin disease precedes the arthritis in nearly 80% of patients. The psoriatic arthritis may precede the psoriasis in up to 15% of patients. Some people may have both at the same time.
The symptoms of psoriatic arthritis can be similar to rheumatoid arthritis, with morning pain and stiffness, along with fatigue. You may have pain and stiffness in the hands, wrists, elbows, shoulders, knees, ankles, feet, and spine.
Arthritis that affects many joints symmetrically is common with psoriatic arthritis. This symmetrical pattern is almost the same as rheumatoid arthritis. At other times, though, it be be asymmetrical, that is not affecting the same joint on both sides of the body. It also tends to affect the last joint ( the DIP that is rarely affected by RA).
With psoriasis you may have thick, inflamed red skin patches (called plaques) covered with white or silvery scales, usually on the elbows, knees, or other areas. In addition, a significant percentage of people with psoriatic arthritis have nail involvement with pitted, discolored, or thickened nails.
Psoriatic arthritis can cause a sausage-like swelling of fingers and toes, which usually occurs when the fingernails are pitted or discolored. In some people with psoriatic arthritis, only one joint is affected yet not the other (one knee only, for example). Sometimes the spine is affected or just the fingers and toes. About 1/3 of patients with psoriatic arthritis have eye problems such as conjunctivitis or pink eye or a more serious eye problem called iritis that is often painful and can lead to loss of vision.