Russell’s sign—named for British psychiatrist Gerald Russell, who first described bulimia nervosa in the 1970s—refers to calluses or sores that frequently occur on the knuckles of those with the disorder. Because many people with bulimia use their hands and fingers to induce vomiting, they may regularly cut their hands on their incisor teeth. Over time, these small cuts may form into scars or large skin lesions. Because not everyone with bulimia purges by vomiting—and not everyone who vomits uses their hands to do so—Russell’s sign is not universally found among people with bulimia.