Our 23 Year Old Son Has A Sore On The

our 23 year old son has a sore on the top of his right foot at the base of his two small toes. It started out feeling sore followed by a bruise about the size of a half-dollar. It then progressed to a nasty-looking sore. He does not recall any injury to his foot. It is painful to the touch and hurts when he walks.