A case of severe hypercalcemia with acute renal failure in sarcoidosis: a diagnostic challenge for the emergency department.

We present and discuss the case of a man admitted to our emergency room because of severe hypercalcemia and renal failure with maintained diuresis. We diagnosed a relapse of sarcoidosis, manifesting as hypercalcemia and renal failure, based on a history of lung sarcoidosis. This is a rare complication of sarcoidosis, due to granulomatous production of vitamin D. This mechanism may have been exacerbated by exposure of sunlight. The initial treatment of the patient was directed towards lowering the circulating calcium level through hyperhydration and forced diuresis, with secondary control of granulomatous activity using corticosteroid therapy. The patient was discharged after 7 days with normal levels of serum calcium, urinary calcium excretion and serum creatinine. Recognition of this rare cause of hypercalcemia is a challenge for the emergency physician.