A 31-year-old woman comes to the office for a yearly checkup. The patient has no medical conditions but expresses dissatisfaction with her appearance and wishes she could lose weight more easily. She reports occasional constipation and fatigue. The patient exercises daily and drinks 1 or 2 glasses of wine 2-3 times a week when socializing with friends. Weight is 58.1 kg (128 lb) and height is 157.5 cm (5 ft 2 in). BMI is 23.4 kg/m2. Routine laboratory evaluation shows a potassium level of 3.1 mEq/L. Physical examination is most likely to show which of the following abnormalities?
Bulimia nervosa | |
Clinical features |
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Physical examination |
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Laboratory findings |
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Hypokalemia in an otherwise healthy young adult with a normal BMI and preoccupation with body shape and weight is concerning for self-induced vomiting associated with bulimia nervosa (BN). BN is characterized by repeated episodes of binge eating followed by compensatory behaviors (eg, vomiting, laxative use, fasting, excessive exercise) to prevent weight gain. Because patients may not be forthcoming about their eating behavior due to embarrassment, physical examination and laboratory assessment can assist in making the diagnosis. Painless bilateral parotid gland enlargement due to repetitive vomiting is a common finding.
Other signs of BN include tachycardia, hypotension, dry skin, calluses or scarring on the dorsum of the hand (Russell sign), and erosion of dental enamel. Common electrolyte abnormalities in BN include hypokalemia and metabolic alkalosis.
(Choices A, B, and D) BN is more commonly associated with tachycardia, dry skin, and hypotension rather than bradycardia (typically seen in anorexia nervosa), diaphoresis, and hypertension.
(Choice C) Goiter can be asymptomatic or associated with symptoms of hypothyroidism or hyperthyroidism. Hypothyroidism can present with fatigue and constipation but would not explain this patient's hypokalemia.
(Choice E) Lanugo hair growth (soft, downy hair typical of newborns) more commonly occurs in anorexia nervosa due to malnutrition.
(Choice F) A malar (butterfly) rash is a characteristic finding in systemic lupus erythematosus, a condition often associated with fatigue. However, other typical findings, including fever, weight loss, and myalgias, are not present in this patient.
Educational objective:
Hypokalemia in an otherwise healthy young adult with a normal BMI and preoccupation with body size is concerning for self-induced vomiting associated with bulimia nervosa. Common physical examination findings in bulimia nervosa include tachycardia, hypotension, painless bilateral parotid gland swelling, calluses or scarring on the dorsum of the hand, and erosion of dental enamel.