Russell's sign named after British psychiatrist Gerald Russell

Gerald Russell

Professor Gerald Francis Morris Russell is a British psychiatrist. In 1979 he published the first description of bulimia nervosa, and Russell's sign has been named after him.-Early life:...

 is a sign defined as calluses on the knuckles or back of the hand due to repeated self-induced vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

 over long periods of time. The condition generally arises from the afflicted's knuckles making contact with the incisor

Incisor

Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...

 teeth during the act of inducing the gag reflex

Gag reflex

The pharyngeal reflex or gag reflex is a reflex contraction of the back of the throat, evoked by touching the soft palate or sometimes the back of the tongue. It prevents something from entering the throat except as part of normal swallowing and helps prevent choking...

 at the back of the throat

Throat

In vertebrate anatomy, the throat is the anterior part of the neck, in front of the vertebral column. It consists of the pharynx and larynx...

 with their finger(s).

This type of scarring is considered one of the physical indicators of a mental illness

Mental illness

A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...

, and Russell's sign is primarily found in patients with an eating disorder

Eating disorder

Eating disorders refer to a group of conditions defined by abnormal eating habits that may involve either insufficient or excessive food intake to the detriment of an individual's physical and mental health. Bulimia nervosa, anorexia nervosa, and binge eating disorder are the most common specific...

 such as bulimia nervosa

Bulimia nervosa

Bulimia nervosa is an eating disorder characterized by binge eating and purging or consuming a large amount of food in a short amount of time, followed by an attempt to rid oneself of the food consumed, usually by purging and/or by laxative, diuretics or excessive exercise. Bulimia nervosa is...

 or anorexia nervosa

Anorexia nervosa

Anorexia nervosa is an eating disorder characterized by refusal to maintain a healthy body weight and an obsessive fear of gaining weight. Although commonly called "anorexia", that term on its own denotes any symptomatic loss of appetite and is not strictly accurate...

. However, it is not always a reliable indicator of an eating disorder.

Bulimics who are capable of "handsfree purging", or the induction of vomiting by the willful opening of the esophageal sphincter in a manner similar to belching, while contracting the stomach muscles, do not have Russell's sign.