Symptoms of the Disease
The disease can take a different course in different patients. Most often, several joints are involved asymmetrically, e.g., the knee, ankle, or elbow. Individual distal joints of the fingers or toes may also be affected (the characteristic “sausage digit” or “radish-like” appearance). Sometimes the inflammatory process involves the joints of the hands and feet symmetrically, and the disease requires differentiation from rheumatoid arthritis (RA). Usually, the rheumatoid factor characteristic of RA is not found in the serum.

In some patients, psoriatic arthritis resembles the course of ankylosing spondylitis, presenting with inflammatory pain in the spine and sacroiliac joints.