Addisonian crisis, or acute adrenocortical insufficiency:

B. Can mimic an acute abdomen with fever, nausea and vomiting, abdominal pain, and hypotension.

DISCUSSION: Addisonian crisis, or acute adrenal insufficiency, may be seen following even mild illness in patients with suppression of the hypothalamic-pituitary-adrenal axis. This suppression can be produced by as little as 1 week of supraphysiologic stress dose steroids in the year before the stressful event. Addisonian crisis is a medical emergency that requires prompt treatment based on clinical suspicion. Clinical findings include fever, nausea and vomiting, abdominal pain, and hypotension. Laboratory analysis may reveal electrolyte abnormalities, including hyponatremia, hyperkalemia, hypoglycemia, and hypercalcemia, as well as eosinophilia on peripheral blood smear. The rapid ACTH test is diagnostic, but it should not delay treatment with intravenous fluid resuscitation, glucose replacement, and high-dose dexamethasone.

Dexamethasone, not hydrocortisone, should be given initially, since it does not interfere with subsequent determination of plasma cortisol. Stress dose steroids are inadequate once adrenal crisis has occurred, and exogenous mineralocorticoids are given when the patient resumes oral intake.