Anorexia Nervosa

For further information, see CMDT Part 29-05: Anorexia Nervosa

Key Features

Essentials of Diagnosis

• Disturbance of body image and intense fear of becoming fat

• Weight loss, leading to body weight 15% below expected

• In females, absence of three consecutive menstrual cycles

General Considerations

• Begins in the years between adolescence and young adulthood

• Cause not known, probably of primary psychiatric origin

• Must exclude medical or psychiatric illnesses that can account for anorexia, weight loss

Demographics

• Occurs most commonly in females (90%), predominantly middle and upper income

• Estimated prevalence

  • 270 cases per 100,000 population for females

  • 22 cases per 100,000 population for males

Clinical Findings

Symptoms and Signs

• Loss of body fat with severe emaciation

• Dry and scaly skin

• Increased lanugo body hair

• Parotid enlargement and edema

• In severe cases, bradycardia, hypotension, and hypothermia

• Cold intolerance

• Constipation

• Amenorrhea

Differential Diagnosis

• Endocrine and metabolic disorders

  • Panhypopituitarism

  • Addison disease

  • Hyperthyroidism

  • Diabetes mellitus

• Gastrointestinal disorders

  • Malabsorption

  • Pancreatic insufficiency

  • Crohn disease

  • Gluten enteropathy

• Chronic infections, eg, tuberculosis

• Cancer, eg, lymphoma

• Rare CNS disorders, eg, hypothalamic tumor

• Severe malnutrition

• Depression

• Obsessive-compulsive disorder

• Body dysmorphic disorder

• Malignancy

• AIDS

• Substance abuse

Diagnosis

Laboratory Tests

• Check for anemia, leukopenia, electrolyte abnormalities, and elevations of blood urea nitrogen and serum creatinine

• Serum cholesterol level often increased

• Luteinizing hormone level depressed and impaired response to luteinizing hormone-releasing hormone

Treatment

Medications

• Tricyclic antidepressants, selective serotonin reuptake inhibitors, and lithium carbonate are effective in some cases

Therapeutic Procedures

• Treatment goal: restoration of normal body weight and improvement in psychological difficulties

• Supportive care

• Structured behavioral therapy

• Intensive psychotherapy

• Family therapy

• Hospitalization may be necessary

• Treatment by experienced teams successful in about two-thirds of cases

Outcome

Complications

• Poor dentition

• Pharyngitis

• Esophagitis

• Aspiration

• Gastric dilatation

• Pancreatitis

• Constipation

• Hemorrhoids

• Dehydration

• Electrolyte abnormalities

Prognosis

• 50% of patients continue to experience difficulties with eating behavior and psychiatric problems

• 2–6% of patients die of the complications of the disorder or from suicide

When to Refer

• Adolescents and young adults with otherwise unexplained weight loss should be evaluated by a psychiatrist

• All patients with diagnosed anorexia nervosa should be co-managed with a psychiatrist

When to Admit

• Signs of hypovolemia, major electrolyte disorders, and severe protein-energy malnutrition

• Failure to improve with outpatient management

References