Bulimia Nervosa
Basics
- Characterized by binge eating (~2,000 kcal) at least once weekly for 3 months
- Inappropriate compensatory behaviors (caloric restriction, vomiting, laxatives, diuretics, excessive exercise)
- Distorted body image and alternating binge/purge cycles
- DSM-5 severity: mild (1-3/week), moderate (4-7), severe (8-13), extreme (≥14)
Epidemiology
- Mean age onset: 18-21 years
- Female predominance (13:1)
- Lifetime prevalence: 0.5% females, 0.08% males (US)
Etiology and Pathophysiology
- Multifactorial: biologic, psychological, environmental, social
- Genetic heritability up to 41%
- Risk factors: female sex, history of obesity/dieting, low self-esteem, depression, anxiety, childhood trauma, substance abuse
Prevention
- Promote realistic healthy weight and self-esteem
- Reduce societal focus on thin ideals
Associated Conditions
- Major depression, anxiety, bipolar, OCD, substance use, borderline personality disorder
- High rates of nonsuicidal self-injury (33%) and suicide attempts (21%)
Diagnosis
History
- Often underreported binge/purge; corroborate from family
- Binge eating episodes, compensatory behaviors
- Use of laxatives, diuretics, ipecac, diet pills
- Menstrual irregularities, fatigue, GI symptoms, dental sensitivity
- Weight fluctuations
Physical Exam
- Tachycardia, peripheral edema
- Dental enamel erosion, parotid swelling
- Russell sign (knuckle calluses)
- Epigastric tenderness
Differential Diagnosis
- Anorexia nervosa (BMI <18.5)
- Major depressive disorder, borderline personality disorder
- Metabolic/endocrine disorders (Addison’s, thyroid, diabetes)
- Pregnancy, genetic syndromes
Diagnostic Tests
- Labs often normal; helpful to assess electrolyte abnormalities, nutritional status
- Screening tools: SCOFF Questionnaire (sensitivity 0.86, specificity 0.83)
- EKG to assess arrhythmias due to electrolyte imbalances
- Pregnancy test
Treatment
General Measures
- Multidisciplinary team: PCP, behavioral health, nutritionist
- Cognitive-behavioral therapy (CBT) first-line
- Family therapy in adolescents
- Nutritional education and relaxation techniques
Medications
- First-line: SSRIs (fluoxetine titrated to 60 mg/day) for symptom reduction
- Maintain therapeutic dose 6-12 months post-remission
- Second-line: other SSRIs (sertraline, escitalopram, fluvoxamine)
- Third-line: TCAs, MAOIs, trazodone, topiramate
- Ondansetron may reduce nausea/vomiting
- Avoid bupropion (seizure risk with electrolyte disturbance)
Issues for Referral
- Specialized eating disorder units for severe cases or medical instability
- Multidisciplinary approach recommended
Admission Criteria
- BMI ≤75% of ideal
- Electrolyte disturbances (hypokalemia, hyponatremia, hypophosphatemia)
- EKG abnormalities (prolonged QTc, bradycardia)
- Hypotension, hypothermia, orthostasis
- Severe medical or psychiatric comorbidities
- Acute food refusal, uncontrollable binges/purges
Inpatient Care
- Supervised meals and bathroom privileges
- Gradual transition of control back to patient
Ongoing Care
Follow-Up
- Monitor binge-purge frequency, self-esteem, depressive symptoms
- Repeat labs weekly until stable
Diet
- Balanced nutrition with regular meal/snack schedule
Patient Education
- Resources: National Alliance on Mental Illness (NAMI)
- Importance of combined psychotherapy and medication for recovery
Prognosis
- 45-70% achieve full recovery or improvement
- 20-30% relapse
- Positive predictors: younger age, shorter illness duration, less frequent symptoms, absence of laxative use, good social support, early treatment response
- Negative predictors: body image obsession, physical abuse history, poor family relations, low motivation, self-harm, personality disorders
Complications
- Substance use disorder
- Electrolyte abnormalities leading to cardiac arrhythmia/arrest
- Gastric dilatation, Mallory-Weiss tears, Boerhaave syndrome
- Suicide risk