200 Anorexia Nervosa and Bulimia Nervosa
Key Points• Patients with anorexia or bulimia are at increased risk for life-threatening metabolic derangements and cardiac dysrhythmias that mandate hospital admission.
• The most common cause of death from anorexia is cardiac arrest secondary to conduction delays or ventricular dysrhythmias.
• Urgent outpatient psychiatric referral is appropriate for well-appearing patients who are able to adequately care for themselves.
Definitions and Epidemiology
Though similar in their relationship with food, these diseases represent two separate psychiatric entities with distinct clinical sequelae. Distinguishing features include the body mass index or height-matched weight and, in women, the presence of regular menstruation. Amenorrhea is a key finding of anorexia in postmenarchal women. Diagnosis requires fulfillment of all criteria listed in the text revision of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) (Box 200.1). These diseases do not coexist in the same patient; a patient has either anorexia or bulimia, but never both simultaneously.1
Box 200.1
DSM-IV-TR Diagnostic Criteria Differentiating Anorexia and Bulimia
1. Recurrent episodes of binge eating:
2. Recurrent inappropriate compensatory behavior to prevent weight gain (vomiting, exercise, laxatives, diuretics)
3. Bingeing and compensatory behavior occurring at least twice per week for 3 months
4. Undue influence of body shape or weight on self-evaluation
5. This disturbance does not occur during an episode of anorexia
From American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 4th ed, text rev (DSM-IV-TR). Washington, DC: American Psychiatric Association; 2000.
Anorexia can be divided into the restricting or binge eating–purging subtypes. Restricting patients commonly eat only 300 to 700 calories each day, or they engage in excessive exercise to ward off weight gain. Binge-purging behavior involves intentional vomiting or the inappropriate use of laxatives, enemas, or diuretics in response to even small amounts of consumed food. Bulimia is similarly divided into purging and nonpurging. The subtypes are based on the behavior occurring at the time of diagnosis.2
Anorexia and bulimia are diseases nearly exclusively encountered in North America, western Europe, and Japan. Childhood anxiety disorders may increase the likelihood of these disorders, although no clear cause has been identified for either illness. Women suffer from anorexia and bulimia more frequently than men do. The lifetime prevalence of anorexia varies from 0.3% to 1% for women; men are estimated to have one tenth of that prevalence. Bulimia is more common than anorexia, with a lifetime prevalence of 1% to 3% in women. Similarly, only 10% of bulimic patients are male; these men are more likely to suffer from premorbid obesity. The incidence is further increased in male wrestlers.3
Presenting Signs and Symptoms
Complications
• Arrhythmia: Disruption of normal cardiac conduction is the most life-threatening medical complication of anorexia. Prolongation of the QTc interval is ominous. Cardiac arrest resulting from conduction delays or ventricular dysrhythmias is the most common cause of death from anorexia.5
• Elevated abdominal pressure: Patients engaging in binge eating may experience severe gastric dilation that significantly increases intraabdominal pressure, either with or without intestinal obstruction. This increased pressure may ultimately result in cardiac arrest from direct mechanical force or decreased venous return.6,7
• Dehydration and renal insufficiency: Insufficient fluid intake may occur with anorexia. With bulimia, prerenal hypovolemia arises from fluid losses as a result of excessive vomiting or laxative abuse.
• Starvation and vitamin deficiency: These conditions result from inadequate caloric intake.
• Osteopenia: Pubescent anorexia or severe bulimia may cause hypoestrogenemia and resultant undermineralized bone. Bone pain or pathologic fractures may ensue.
• Electrolyte abnormality: This condition results from either insufficient intake or excessive gastrointestinal losses.
• Esophageal and gastric trauma: Repetitive, forceful vomiting may lead to Mallory-Weiss tears or Boerhaave syndrome. Gastric distention occurs with binging.
• Nausea and constipation: Gastrointestinal motility decreases with starvation. Native colonic contraction decreases with laxative abuse, thereby leading to colonic distention and constipation.
• Rectal prolapse: This condition results from muscle weakening secondary to laxative abuse.
• Congestive heart failure: Cardiomyopathy may be caused by starvation states or by ipecac abuse.
• Refeeding syndromes: Peripheral edema, hypophosphatemia, and dysrhythmias are common features associated with resumption of appropriate caloric intake.
• Inattention and changes in mental status: Chronic disease may lead to decreases in both gray matter and white matter along with concurrent ventricular enlargement. Starvation-associated hypoglycemia or other electrolyte abnormalities may affect mental status.
Associated Comorbid Conditions
• Anxiety disorders: The lifetime prevalence is 64% in eating-disordered patients versus 13% in the general population. Obsessive-compulsive disorder and social phobia are common.8
• Substance abuse: This is often seen in patients with binge-type bulimia.9
• Personality disorders: Obsessive-compulsive personality disorder is associated with anorexia; cluster B disorders are more frequently identified in patients with bulimia.9
Differential Diagnosis
Evaluation of a patient with cachexia must be thorough. A notable lack of subjective complaints in an emaciated patient may be cause to suspect anorexia. The differential diagnosis of anorexia and bulimia is narrow because the patient’s behavior is an essential component of the disease. Catabolic states associated with increased caloric consumption, such as infection or hypermetabolism, should be differentiated from inadequate caloric intake (Box 200.2).
Diagnostic Testing
No ancillary tests are available to confirm the diagnosis of anorexia or bulimia. The diagnosis is made by following the guidelines set forth in the DSM-IV-TR. Screening tools have been developed to aid in the diagnosis of both these eating disorders; the SCOFF questionnaire proposed by Morgan et al. is one such tool. Answering “yes” to two or more of the SCOFF questions is 100% sensitive for both anorexia and bulimia.10 The SCOFF screen includes the following questions: Do you induce vomiting because you feel uncomfortably full? Do you worry that you have lost control over how much you eat? Have you recently lost more than 14 lb in the last 3 months? Do you think you are fat even when other people say you are too thin? Does food dominate your life?
Laboratory tests aid in identification of the potentially life-threatening physiologic abnormalities commonly seen in an eating-disordered patient. Serum electrolytes, including phosphorus, are critical in the evaluation of patients with suspected anorexia or bulimia. Hypokalemic, hypochloremic metabolic alkalosis is the most common finding in patients with induced vomiting. Laxative abuse results in metabolic acidosis from intestinal loss of bicarbonate. Endocrine abnormalities may be encountered in patients with chronic disease; insufficient thyroid hormone may cause hypotension, hypothermia, and bradycardia. An elevated serum amylase level may serve as useful evidence of surreptitious vomiting, although the degree of increase in the serum value itself has little clinical significance (Table 200.1).
| LABORATORY ABNORMALITY DIAGNOSIS | FINDING |
|---|---|
| Hypokalemia, hypochloremia, alkalosis (elevated HCO3− or pH); elevated amylase | Excessive vomiting |
| Hypokalemia, acidosis (decreased HCO3− or pH) | Diarrhea |
HCO3−, Bicarbonate.
Intracranial imaging reveals loss of gray matter.8 Such imaging studies are indicated only for patients with altered mental status or trauma (see the “Priority Actions” box).
Priority ActionsTreatment
Sophisticated and concurrent psychologic, social, dietary, and medical support is crucial for both inpatients and outpatients. Selective serotonin reuptake inhibitors, in particular fluoxetine, have been associated with increased compliance in the outpatient treatment of bulimia and may also address the anxiety states commonly encountered with eating disorders. Antidepressants should not be initiated in the ED without the collaboration of the treating psychiatrist or primary physician.11,12
Disposition
Current guidelines suggest psychiatric or medical admission for any child or adolescent with rapid weight loss. Parents or guardians may request inpatient admission when outpatient management has failed. Psychiatric admission for minors is typically easier to accomplish than for adults. Early inpatient treatment is associated with a decreased risk for both arrhythmias and loss of cortical volume. Admission should be advocated for all patients who lack home support or who are otherwise at risk for failure of outpatient treatment (Box 200.3).13,14
Barring clear impairment of decision-making capacity, involuntary admission of adults is rare. The judicial system in the United States generally recognizes that a patient’s actions supersede stated intent, thus supporting hospitalization of patients who are at significant risk for self-harm. For example, an anorexic patient may deny suicidality despite behavior that clearly resulted in a life-threatening dysrhythmia. Involuntary admission should be considered for patients with such profound lack of insight, as well as for those who lack decision-making capacity.5,15
American Psychiatric Association Work Group on Eating Disorders. Practice guideline for the treatment of patients with eating disorders (revision). Am J Psychiatry. 2000;157(Suppl):1–39.
Morgan JF, Reid F, Lacey JH. The SCOFF questionnaire: a new screening tool for eating disorders. West J Med. 2000;172:164–165.
Yager J, Andersen AL. Anorexia nervosa. N Engl J Med. 2005;353:1481–1488.
1 American Psychiatric Association. Diagnostic and statistical manual of mental disorders. text rev. 4th ed. Washington, DC: American Psychiatric Association; 2000.
2 Yager J, Andersen AL. Anorexia nervosa. N Engl J Med. 2005;353:1481–1488.
3 Kessler R, McGonagle K, Zhao S, et al. Lifetime and 12-month prevalence of DSM-III-R psychiatric disorders in the United States: results from the National Comorbidity Survey. Arch Gen Psychiatry. 1994;51:8–19.
4 Lapid MI, Prom MC, Burton MC, et al. Eating disorders in the elderly. Int Psychogeriatr. 2010;22:523–536.
5 Melamed Y, Mester R, Margolin J, et al. Involuntary treatment of anorexia nervosa. Int J Law Psychiatry. 2003;26:617–626.
6 Ikegaya H, Nakajima M, Shintani-Ishida K, et al. Death due to duodenal obstruction in a patient with an eating disorder: a case report. Int J Eat Disord. 2006;39:350–352.
7 Kim SC, Cho HJ, Kim MC, et al. Sudden cardiac arrest due to acute gastric dilatation in a patient with an eating disorder. Emerg Med J. 2009;26:227–228.
8 Kaye W, Bulik C, Thornton L, et al. Comorbidity of anxiety disorders with anorexia and bulimia nervosa. Am J Psychiatry. 2004;161:2215–2221.
9 Jordan J, Joyce PR, Carter FA, et al. Specific and nonspecific comorbidity in anorexia nervosa. Int J Eat Disord. 2008;41:47–56.
10 Morgan JF, Reid F, Lacey JH. The SCOFF questionnaire: a new screening tool for eating disorders. West J Med. 2000;172:164–165.
11 Kaye W, Bailer U, Frank G, et al. Brain imaging of serotonin after recovery from anorexia and bulimia nervosa. Physiol Behav. 2005;86:15–17.
12 Walsh B, Fairburn C, Mickley D, et al. Treatment of bulimia nervosa in a primary care setting. Am J Psychiatry. 2004;161:556–561.
13 Keel P, Dorer D, Eddy K, et al. Predictors of mortality in eating disorders. Arch Gen Psychiatry. 2003;60:179–183.
14 American Psychiatric Association Work Group on Eating Disorders. Practice guideline for the treatment of patients with eating disorders (revision). Am J Psychiatry. 2000;157(Suppl):1–39.
15 Watson TL, Bowers WA, Andersen AE. Involuntary treatment of eating disorders. Am J Psychiatry. 2000;157:1806–1810.
