Russell’s sign is a physical indicator defined by the presence of calluses, abrasions, or scars on the back of the hand, specifically over the knuckles. This dermatological manifestation is a consequence of a specific compensatory behavior. The sign develops from the repetitive trauma of skin rubbing against a hard surface. This physical marker is named after British psychiatrist Gerald Russell, who first described the finding in patients with an eating disorder.
Physical Description and Cause
Russell’s sign is generally observed as areas of thickened, rough, or discolored skin on the dorsal aspect of the hand, most frequently affecting the knuckles of the index and middle fingers. The appearance can range from slight hyperkeratosis, or skin thickening, to more pronounced scarring or small lacerations. These lesions typically form on the dominant hand, as this is the hand most often used to manually stimulate the gag reflex during purging episodes.
The precise mechanism involves repeated friction against the incisor teeth. When a person uses their fingers to induce vomiting, the knuckles scrape against the sharp edges of the teeth. This repeated mechanical trauma prevents the skin from healing properly, resulting in the characteristic callused or scarred appearance. The development of Russell’s sign suggests a history of persistent, frequent purging behavior over a significant duration.
Clinical Significance
The presence of Russell’s sign strongly suggests a history of self-induced vomiting. It is most commonly associated with Bulimia Nervosa (BN) or the purging subtype of Anorexia Nervosa. However, this physical finding is not a standalone diagnostic tool, as some individuals who purge use other methods and will not exhibit the sign.
For clinicians, observing this sign prompts a thorough screening for an eating disorder and its associated health complications. While the knuckles themselves may not suffer permanent harm, the underlying behavior poses a serious risk, including severe electrolyte imbalances that can affect heart function, dental enamel erosion from stomach acid, and potential damage to the esophagus. The sign serves as an objective, observable clue that helps medical professionals initiate a full assessment to establish a complete clinical picture.
Intervention and Support Resources
Recognizing Russell’s sign should be an immediate catalyst for seeking professional help, as the physical manifestation is secondary to a serious underlying psychological condition. The first step involves consultation with a medical doctor to assess internal physical damage, such as electrolyte abnormalities, which require immediate medical stabilization. Following this, the focus must shift to comprehensive treatment for the eating disorder itself, which involves a multidisciplinary team.
Treatment typically includes a mental health professional specializing in eating disorders and a registered dietitian. Evidence-based therapies like Enhanced Cognitive Behavioral Therapy (CBT-E) or Family-Based Treatment (FBT) are frequently used to address the thoughts and behaviors driving the purging cycle. Accessible resources are available for immediate support, including the National Eating Disorders Association (NEDA) helpline or the Alliance for Eating Disorders Awareness, which can provide confidential information and treatment referrals. Recovery requires addressing the behavioral patterns and the deep-seated emotional distress.