10 Psoriatic Arthritis Symptoms
Psoriatic arthritis can sometimes cause flexion deformity, in which fingers are pulled out of their normal alignment.
About 5% of people with psoriatic arthritis develop the most severe form of the disease, called psoriatic mutilans. Without treatment, this can cause destruction of multiple joints, often in the hands, feet, neck, and lower back. When it affects the hands, it can cause telescoping fingers.
This occurs when finger bones are reabsorbed into the body, causing tissue collapse. The fingers can shrink down into themselves in a telescoping fashion.