A 42-year-old woman comes to the emergency department due to 2 syncopal episodes in the last 3 days. The patient was well until approximately a month ago when she began to feel increasingly fatigued and weak. For the past 2 weeks, she has had anorexia, nausea, and abdominal pain. The patient's medical history is unremarkable, and she takes no medications. She drinks wine only on social occasions, and does not use tobacco or illicit drugs. Temperature is 36.7 C (98 F), blood pressure is 86/52 mm Hg, pulse is 90/min, and respirations are 18/min. Cardiopulmonary examination is normal. The abdomen is mildly tender with otherwise normal findings. The skin shows hyperpigmentation in the palmar creases. Which of the following additional findings is most likely present in this patient?
Primary adrenal insufficiency | |
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Treatment |
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This patient has typical features of primary adrenal insufficiency (PAI), also known as Addison disease. The initial symptoms of PAI often are nonspecific and can include fatigue, malaise, weakness, and weight loss. Gastrointestinal symptoms (eg, nausea, abdominal pain, diarrhea) occur in up to 90% of patients. Aldosterone deficiency causes volume depletion and cortisol deficiency causes loss of vascular tone; these changes can manifest as hypotension, postural dizziness, or syncope. Skin signs can include generalized or patchy hyperpigmentation (due to cosecretion of melanocyte-stimulating hormone with ACTH) and sometimes vitiligo (due to autoimmune destruction of melanocytes).
The secretion of antidiuretic hormone (ADH) is increased in PAI; this results from both nonosmotic stimulus for ADH release in the setting of hypovolemia and reduced inhibition of ADH in the setting of reduced cortisol. With increased ADH secretion there is increased water retention that leads to hyponatremia, the most common electrolyte abnormality in PAI. Aldosterone deficiency also leads to renal potassium retention; therefore, hyperkalemia is usually present as well.
(Choice A) Hypoglycemia is a potential complication of cortisol deficiency in PAI, and can be triggered by fasting, infection, or alcohol consumption. Hyperglycemia is not seen in the absence of preexisting type 1 diabetes mellitus.
(Choice C) Hyponatremia, rather than hypernatremia, is the most common electrolyte abnormality in PAI and is due to increased ADH secretion.
(Choice D) PAI can cause mild hypercalcemia due to increased release of calcium from the bones, increased proximal tubular calcium absorption, and volume contraction. PAI with concurrent hypoparathyroidism leading to hypocalcemia can be seen in the polyglandular autoimmune syndrome type 1 but is extremely rare.
(Choice E) In addition to potassium retention, aldosterone deficiency also stimulates renal retention of hydrogen and chloride ions, leading to a mild hyperchloremic metabolic acidosis.
Educational objective:
Chronic primary adrenal insufficiency presents with weight loss, fatigue, and gastrointestinal symptoms. Volume depletion and reduced vascular tone can cause hypotension and syncope. Most patients have hyponatremia due to renal sodium loss and increased secretion of antidiuretic hormone. Hyperkalemia is also common due to renal potassium retention in the setting of aldosterone deficiency.