A 21-year-old woman presents with fatigue that has been present for 6 months. History reveals a diagnosis of asthma and chronic rhinosinusitis that are well controlled with albuterol and fluticasone nasal spray. The patient denies drugs, alcohol, or sexual activity. She has a temperature of 37°C, blood pressure of 120/80 mmHg, heart rate of 75 beats per minute, respiratory rate of 16 breaths per minute, and oxygen saturation of 100% on room air. Physical examination reveals dental erosions and the patient refuses to take her hands out of her pockets. Laboratory studies reveal the following:
Based on these findings, what is the most likely diagnosis?
A. Diuretic abuseSurreptitious vomiting. The patient in this question has the diagnosis of surreptitious vomiting. The combination of dental erosions, metabolic alkalosis, and hypochloremia makes this the correct answer. The patient also has a low urine chloride concentration. (A) Diuretic abuse should definitely be considered in this clinical scenario as patients with diuretic abuse also present with hypokalemia and metabolic alkalosis; however, their urine chloride concentrations are usually high. (C) Diabetic ketoacidosis (DKA) results in metabolic acidosis (with anion gap), not metabolic alkalosis. (D) Primary hyperaldosteronism is caused by adrenal hyperplasia or by an aldosterone-secreting adrenal adenoma. This results in hypertension, hypokalemia, metabolic alkalosis, and low plasma renin. The patient in this question is normotensive, making this diagnosis unlikely.