What is Raynaud’s phenomenon? Raynaud’s phenomenon is a condition that causes the blood vessels in the hands and feet to narrow, decreasing blood flow. When this happens, parts of the body—usually the fingers and toes—become cold and numb, and change color (usually, to white or blue). An attack usually happens from exposure to cold or stress.
What is psoriatic arthritis? Psoriatic arthritis is a condition that causes swelling and pain in joints and the places where tendons and ligaments attach to bones. Most people who develop psoriatic arthritis already have psoriasis (a skin disease), but a small number have joint pain before the skin rash.