Dr. Kirkby is a family medicine physician in private practice in Pietermaritzburg, KwaZulu-Natal, South Africa, and an editor for DynaMed. Dr. Brown is deputy editor for DynaMed (www.dynamicmedical.com), a database of comprehensive updated summaries covering nearly 2,000 clinical topics.
Description
• Characterized by restrictive eating to the point of self-starvation, or binge-purging (vomiting, use of laxatives or diuretics), both leading to severe self-induced weight loss
ICD-9 codes
• 307.1 anorexia nervosa
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Prevalence
• 1.2% women and 0.29% men
• Peaks in adolescence
Risk factors
• Dieting and psychiatric comorbidity
• Family history of eating disorders
Early warning signs
• Persistent dieting
• Arrest in weight gain during puberty
• Social isolation
• Compulsive exercise
• Preoccupation with thinness and body image
Complications
• Increased mortality and suicide risk
• Cardiac complications
• Osteoporosis
• Increased incidence of anemia and hyperemesis during pregnancy; reduced fetal growth
• End-organ damage from malnutrition
• Metabolic disturbances—hypokalemia, hypothermia, endocrinopathy
• Cognitive changes, depression
• Infertility
• Refeeding syndrome (cardiac failure in return to eating following prolonged starvation) with profound hypophosphatemia
Associated conditions
• Depression
• Anxiety disorders, including social phobia, simple phobia, obsessive-compulsive disorder
• Bulimia
• Psychoactive substance-use disorder
History
• May be brought to caregiver’s attention by relative/friend
• Premenarchal girls have height and weight deficits.
• Refusal to maintain weight over minimal normal, leading to body weight 15% below expected*
• Amenorrhea for at least three consecutive months*
• Intense fear of gaining weight or becoming fat even though underweight*
• Disturbance in image of weight or shape, undue influence of body weight or shape on self-evaluation, or denial of seriousness of current low body weight*
• Persistent desire to lose weight despite emaciation
• Excessive exercise
• Purging via laxative or diuretic abuse, ipecac ingestion
Possible exam findings
• Cachexia
• Decreased vital signs and lethargy
• Hyperactivity despite malnutrition (typical)
• Reluctance to be weighed
• Dry skin
• Lanugo hair
• Hair loss
• Hypercarotenemia
• Cutting, burning, or other signs of self-afflicted harm
• Peripheral edema
Differential diagnoses
• Hypothalamic or pituitary tumor
• Cancer
• Depression
• Schizophrenia
• Hyperthyroidism
• Addison’s disease
• Autoimmune disease
• GI disorders
Possible abnormal test results
• Pancytopenia
• Electrolyte imbalance
• Decreased total protein and albumin
• Low or normal erythrocyte sedimentation rate
• Endocrine abnormalities
• MRI findings of decreased gray and white matter and increased cerebrospinal fluid volume
• ECG findings of bradycardia or prolonged QT interval
Screening
• SCOFF acronym may be useful (two or more positive answers suggests eating disorder)
— Do you make yourself Sick because you feel uncomfortably full?
— Do you worry you have lost Control over how much you eat?
— Have you recently lost Over 10 pounds in a three-month period?
— Do you believe yourself to be Fat when others say you are too thin?
— Would you say that Food dominates your life?
Treatment
• Hospitalization if weight <75%-85% ideal or there is medical decompensation
• American Dietetic Association recommendations:
— Gradual adjustments in nutrient intake and weight progress — Stepping up daily caloric intake from baseline level of 30-40 kcal/kg of weight (starting at 1,000-1,200 kcal
per day) to achieve weight gain of 0.5-1 lb (0.23-0.45 kg) per week
— Eventual goal is restoration of healthful weight and resumption of normal eating patterns.
• Limited evidence for behavioral treatment
— Most evidence in adolescents related to family therapy
♦ Family therapy might be associated with faster return to health than individual therapy in adolescents.
♦ Different family therapy approaches appear to have similar efficacy in adolescents.
— Counseling therapies with limited evidence of benefit in adults include cognitive-behavioral therapy, focal psychotherapy, and family therapy.
• Evidence for medications sparse and inconclusive
• Specialist consultants may include psychiatrist, psychologist, dietitian.
• Maintain weight >75% ideal body weight to reduce risk for amenorrhea and osteoporosis.
Prognosis • Variable—spontaneous remission common, or may evolve to bulimia
• Typical case is chronic and relapsing.
• Often treatment-resistant, but many patients recover.
• Treatment dropout rates are high.
• Predictor of treatment completion is high self-esteem.
See www.dynamicmedical.com for references.
