A 21-year-old college student comes to the office due to swelling in her feet and ankles. The patient noticed the swelling a few days ago when her shoes would not fit. She says, "I have become so fat and have such low energy since coming to college even though I run every day and eat only healthy foods. I am also worried about my grades because my concentration is so poor." The patient has a medical history of chondromalacia patellae, which she uses a knee brace for during runs. Physical examination shows a thin habitus, dry skin, excoriations on her forearms, 2+ pitting edema of her ankles, and a distended abdomen with hypoactive bowel sounds. Temperature is 37.2 C (99 F), blood pressure is 85/60 mm Hg, pulse is 50/min, and respirations are 14/min. BMI is 17 kg/m². Which of the following abnormalities is most likely present in this patient?

Question

Quizplus · Accepted Answer

11ec25c8_d39f_92ff_bc81_757e2a210a9d_MD0003_00 This patient's low BMI and distorted body image are suggestive of anorexia nervosa (AN). Weight loss and chronic malnutrition lead to dysfunction in multiple organ systems. This patient's clinical presentation of dry skin causing scratching and excoriations, edema, abdominal distension, hypoactive bowel sounds, and vital sign abnormalities (eg, hypotension, bradycardia) is consistent with medical complications due to AN. Gastroparesis and abdominal bloating are common. Edema is caused by electrolyte and fluid disturbances and is commonly seen in the ankles and around the eyes. Decreased bone mineral density is due to a combination of factors-including various endocrine abnormalities, hypercortisolism, and growth hormone resistance-that result in an increased risk of bone fractures. Other complications include hypercarotenemia, accelerated metabolism of cholesterol leading to hypercholesterolemia, cardiac atrophy, arrhythmias, amenorrhea, lanugo, and seizures. (Choices B and C) Electrolytes, including magnesium, potassium, sodium, and phosphate, may be normal or depleted rather than increased. Hypokalemia due to self-induced vomiting is a common feature in patients with the binge-eating/purging subtype of AN. (Choice D) Hypocarotenemia is not classically associated with AN. Hypercarotenemia, which presents with yellowing skin, particularly in the palms, can be seen in patients with AN. It is due to excessive consumption of low-calorie, carotene-rich foods (eg, carrots, squash) and impairment in hepatic clearance. (Choice E) The suppression of the hypothalamic-pituitary-ovarian axis in AN results in decreased GnRH and LH levels, with resultant amenorrhea and infertility. (Choice F) Primary hypothyroidism would not explain this patient's low BMI and distorted body image. Thyroid abnormalities can occur in AN as an adaptation to chronic nutritional depletion; however, these abnormalities commonly present as euthyroid sick syndrome. The T3 and/or T4 may be low while the TSH is normal to low rather than elevated, as in primary hypothyroidism. Educational objective: Anorexia nervosa is characterized by a distorted body image and fear of weight gain despite an abnormally low BMI. Medical complications due to malnutrition include bradycardia, hypotension, edema, gastroparesis, cardiac atrophy, and decreased bone mineral density. References: Medical complications of anorexia nervosa and their treatments: an update on some critical aspects. (http://www.ncbi.nlm.nih.gov/pubmed/26138740) Medical complications of anorexia nervosa. (http://www.ncbi.nlm.nih.gov/pubmed/27166107)

A 21-Year-Old College Student Comes to the Office Due to Swelling