Eating disorders, such as anorexia nervosa, bulimia nervosa, and binge-eating disorder, are psychological pathologies characterized by disordered relationships with food. Eating disorders are challenging to diagnose in the ED because physical manifestations may be subtle and historical features may not be elicited unless the disorder is suspected from medical complications or comorbidities. It is important for the emergency physician to recognize these conditions, however, because they are among the most deadly of psychiatric illnesses.¹ The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders refines the diagnostic criteria of eating disorders from the previous edition (Table 291-1).²

There are two subtypes of anorexia, restrictive and binge/purge, with crossover between the two subtypes.³ Patients with a predominantly restrictive pattern simply minimize their food intake. Patients with a predominantly binging/purging subtype make up for unaccepTable food intake with diuretics, laxatives, enemas, or vomiting. There are also two subtypes of bulimia: purging and nonpurging. Those who purge do so by the above methods; those classified as nonpurging may use compensatory methods such as fasting or excessive exercise. There is a moderate amount of crossover between anorexia and bulimia, with up to 50% of anorexia patients eventually developing bulimia.⁴ Binge eating disorder is characterized by habitual, recurrent binge consumptions that cause significant distress and is distinct from simple episodic overeating.

Anorexia nervosa has an overall incidence rate of 8 per 100,000 person-years,⁵ with an estimated lifetime prevalence of 0.9% in women and 0.3% in men.⁶ There is no significant difference in prevalence of anorexia between different races or ethnicities.⁷ Bulimia nervosa has an overall incidence rate of 12 per 100,000 person-years,⁵ with an estimated lifetime prevalence of 1.5% in women and 0.5% in men.⁶ Bulimia is more common in Latinos (lifetime prevalence of 2.03%) and African Americans (1.31%) than in whites (0.51%).⁷ Binge eating disorder is relatively more common in older individuals and males than both anorexia and bulimia.⁵ It is also more prevalent in minority groups than in non-Latino whites.⁷ In the United States, the incidence rate for those ≥14 years old is 1010 per 100,000 person-years in females and 660 per 100,000 person-years in males,⁸ with a lifetime prevalence of 3.5% in women and 2.0% among men.⁶ Although it is often associated with obesity, binge eating disorder is a distinct disorder.⁹

There are several biologic and psychosocial factors that predispose toward disordered eating. There is evidence that eating disorders run in families,¹⁰ possibly related to both genetic influences and similar underlying temperaments and behaviors.¹¹ Development of eating disorders has historically been associated with dysfunctional reward processing in relation to food,¹² but the pathogenesis of this abnormal response is not well understood.¹³ MRI studies detect altered subcortical and cortical brain behavior as well as structural brain differences in patients with eating disorders compared to normal controls. Some of these studies implicate differences in brain regions involved in reward processing, but results are inconsistent.^14,15,16 Patients with eating disorders also demonstrate differences in certain peripheral and central chemical modulators involved in eating behavior and energy homeostasis compared to controls, but it is not known if such changes are causal or correlative.¹⁷

HISTORY

Patients with eating disorders often present to the ED with vague signs and symptoms, such as weakness, fatigue, pallor, dizziness, syncope, confusion, bloating, edema, or persistent nausea.¹⁸ Alternatively complaints may be due to medical complications, such as chest pain and hematemesis caused by a Mallory-Weiss tear from purging; palpitations from electrolyte-induced dysrhythmias; dysmenorrhea from disruption of the hypothalamic-pituitary axis; or fractures from osteoporosis or extreme exercise. Depression, anxiety, substance abuse, self-injurious behavior, or suicidality may coexist.^19,20 A meta-analysis of 36 studies reviewing mortality rates for patients with eating disorders reported that one in five individuals with anorexia who died had committed suicide.²¹ Data on patients with bulimia or binge eating disorder are confounded by crossover diagnoses. Therefore, if an eating disorder is suspected, consider screening for depression and suicidality.

If clinical suspicion is raised for an eating disorder based on complaint cluster, physical examination, or family report, explore a more focused history. Important data points to elicit include eating and dieting behavior; desire for weight loss; typical daily dietary intake; presence or absence of calorie counting; compensatory exercise behavior; guilt patterns following eating; menstruation pattern; and use of over-the-counter dietary supplements or laxative agents. Certain sensitive history points may be difficult to elicit in the ED, such as early childhood GI issues or picky eating or obesity, self-esteem issues, societal thinness pressures, teasing, propensity toward perfectionism, or sexual abuse. Certain physical activities raise risk for eating disorders, such as gymnastics, ballet and other dance, wrestling, swimming, and cross-country running.^22,23,24 Because eating disorders are characterized by denial of symptoms and behaviors, when eliciting history, take a nonjudgmental approach to encourage trust and truthful disclosure.¹⁹

PHYSICAL EXAMINATION

Patients with anorexia are typically easily identifiable based on a very thin body habitus. Other possible signs include hypotension (resting or orthostatic); bradycardia or tachydysrhythmia; or hypothermia. Patients may also exhibit signs of vitamin deficiencies such as brittle, flaking, or ridged nails (nonspecific malnutrition); stomatitis or cheilitis (B vitamin deficiency); or perifollicular petechiae (scurvy). They may also develop fine, long hair on the arms and face, acral cyanosis (impaired thermoregulation), and/or pretibial edema secondary to malnutrition.¹⁹

Patients with bulimia or binge eating disorder can be difficult to detect in the ED because they tend to be normal weight or even slightly overweight. Consider eating disorder diagnoses in the presence of other physical indicators, even in normal weight or overweight patients. Self-induced vomiting can cause painless hypertrophy of the parotid glands, dental erosion, and trauma or callous formation to the dorsal hands (Russell’s sign),²⁵ as well as pharyngeal erythema or abrasions, gingivitis, facial petechiae or subconjunctival hemorrhage, and halitosis. Laxative abuse may cause peripheral edema, anal fissures, hemorrhoids, perianal dermatitis, and rectal bleeding. Binge eating disorder may have no abnormalities apparent on physical examination.

The SCOFF questionnaire (Table 291-2) is useful for screening for anorexia and bulimia in a brief ED encounter and can be remembered by its acronym: Sick, Control, One stone, Fat, Food.²⁶ Other screening tools are more extensive and are more useful in a primary care setting. For reference, the Eating Disorder Diagnostic Scale is a 22-point questionnaire that is self-administered and can identify risk for all three major eating disorders.²⁷ The Eating Attitudes Test is nonspecific and can identify need for referral to a mental health professional for further evaluation.²⁸ The Questionnaire on Eating and Weight Patterns-Revised is specific for binge eating disorder and displays a reasonable level of concordance between its scores and diagnostic interviews.²⁹

DIFFERENTIAL DIAGNOSIS

Consider organic pathology in the assessment of a patient with a potential eating disorder (Table 291-3).