Hypercalcemia in a patient with hypoparathyroidism and Nocardia asteroides infection: a novel observation

Hypercalcemia is associated with numerous chronic granulomatous processes and chronic infections. Increased production of 1,25-dihydroxyvitamin D by activated macrophages has been shown to be the cause in most cases. In this article, we describe a case of hypercalcemia related to infection with Nocardia asteroides. In a 34-year-old woman who previously had hypocalcemia, acute hypercalcemia developed coincident with Nocardia pericarditis. The hypercalcemia resolved after treatment of N. asteroides with sulfisoxazole. Parathyroid hormone and phosphorus levels were within normal limits, and total 25-hydroxyvitamin D levels were only mildly increased. After successful treatment of the Nocardia infection, the patient required supplemental calcium and vitamin D. Her hypercalcemia was temporally related to the duration of the N. asteroides infection. We believe this is the first reported case of hypercalcemia associated with N. asteroides infection.