Snapshot A 22-year-old woman presents to her university health center for a primary care appointment. She admits that she thinks she is "fat" and feels extremely self-conscious about her body. She describes having various periods of strict dieting interspersed with days when she binges on candy bars and dessert foods. She says that she would keep the candy bars and desserts hidden in her closet and eat them late at night when her roommates would not be able to observe her. She notes that although she feels some relief immediately after a binge, she feels extremely distressed afterwards and has started making herself throw up. She is engaging in binge-purge episodes about 5 to 6 times per week. Her BMI is 21 kg/m2. Introduction Overview bulimia nervosa is an eating disorder marked by recurrent episodes of binge eating accompanied by compensatory behaviors (e.g. purging) Epidemiology prevalence 1% in the US 0.5% for males 1.5% for females demographics females > males risk factors jobs or hobbies that require rapid gain or loss of weight (e.g. wrestling and bodybuilding) or emphasize a thin body type (e.g., ballet and cheerleading) Pathophysiology result of a complex of psychosocial factors Prognosis ~50% of patients with bulimia will recover fully ~30% of patients have partial recovery while 10-20% continue to have chronic symptoms Presentation Symptoms recurrent episodes of binge-eating followed by compensatory behavior eating a large amount of food in a discrete period of time feeling loss of control during the episode common compensatory behaviors self-induced vomiting laxative use excessive exercise restrictive eating episodes occur at least once a week for 3 months Physical exam weight often normal or slightly above ideal body weight (> 18.5 kg/m2) parotid gland enlargement dental cavities Russell sign dorsal hand calluses from inducing vomiting Studies Basic metabolic panel may show electrolyte abnormalities hypokalemic metabolic alkalosis with significant vomiting ECG QT-interval prolongation, especially in the setting of hypokalemia, indicates serious risk for cardiac arrhythmias Differential Anorexia nerviosa key distinguishing factor food and calorie restriction; lower-than-normal BMI Binge-eating disorder key distinguishing factor episodes of binging that are not accompanied by compensatory behaviors Treatment Lifestyle cognitive behavioral therapy first-line treatment Medical selective serotonin reuptake inhibitors (SSRIs) (e.g., fluoxetine) particularly helpful for patients with concurrent symptoms of depression and anxiety indicated in patients who have suboptimal response to cognitive behavioral therapy Complications Electrolyte disturbances hypokalemia metabolic alkalosis