Bulimia Nervosa

Psychiatry

Overview

Definition

An eating disorder characterized by recurrent episodes of binge eating followed by inappropriate compensatory behaviors (purging, fasting, or excessive exercise) to prevent weight gain, while maintaining a normal or near-normal body weight.

Epidemiology

Prevalence ~1-2% in young women. Average age of onset is late adolescence.

Etiology & Risk Factors

  • Sociocultural factors, low self-esteem, serotonin dysregulation

Clinical Symptoms

  • Recurrent binge eating (consuming an abnormally large amount of food with a sense of lack of control)
  • Recurrent compensatory behaviors: Self-induced vomiting, misuse of laxatives/diuretics, fasting, or excessive exercise
  • Binge/compensatory cycles occur at least once a week for 3 months
  • Preoccupation with body shape and weight
  • Physical signs of purging: Russell's sign (calluses on knuckles from inducing vomiting), dental enamel erosion (due to gastric acid), parotid gland hypertrophy ('chipmunk cheeks')
  • *Note: Unlike anorexia, patients are typically normal weight or overweight*

Clinical Approach

Diagnosis

  • DSM-5 criteria: Binge eating + purging once a week for 3 months with normal/high weight
  • Electrolyte check (hypokalemia, hypochloremic metabolic alkalosis from vomiting)

Management

  • Cognitive Behavioral Therapy (CBT-E, first-line, highly effective)
  • Nutritional counseling
  • Pharmacotherapy: Fluoxetine (SSRI, approved at high dose of 60mg/day to reduce binge/purge cycles)
  • *Note: Bupropion is ABSOLUTELY CONTRAINDICATED due to high risk of seizures in purging patients*

Complications

  • Severe hypokalemia / Cardiac Arrhythmias
  • Esophageal tears (Mallory-Weiss) / Boerhaave syndrome
  • Severe dental decay
  • Laxative dependence