“Buerger disease is a rare disease of the arteries and veins in the arms and legs. In Buerger disease — also called thromboangiitis obliterans — blood vessels become blocked. This reduces blood flow to the affected areas. Blood clots may form in the blood vessels.
Over time, the lack of blood flow damages or destroys skin tissue. The damage can lead to infection and death of body tissue, called gangrene. Buerger disease is usually first seen in the feet. It may eventually affect the blood vessels of the hand.”
MAYO Clinic