Single Dose Of Bisphosphonate To Treat Infantile Hypercalcemia

ABSTRACT Objective: To describe a case of subcutaneous fat necrosis (SCFN) treated with a single dose of bisphosphonate. Methods: We present the clinical, laboratory, and radiologic findings in an infant with severe hypercalcemia secondary to SCFN and the unique treatment course, as well as a review of relevant literature. Results: A term neonate with history of hypoxic ischemic encephalopathy status post therapeutic cooling was referred for severe hypercalcemia. At 2 weeks of life, he developed pink, indurated confluent plaques on his back and posterior upper arms, consistent with SCFN. Laboratory data showed a calcium level of 17.6 mg/dL and ionized calcium of 8.98 mg/dL. Parathyroid hormone was adequately suppressed at <3 pg/mL. Serum 1,25-dihydroxyvitamin D was elevated at 106 pg/mL and 25-hydroxyvitamin D appropriate at 31 ng/mL. Hypercalcemia persisted at 14.5 mg/dL despite aggressive hydration and furosemide, and the infant developed tachypnea. Pamidronate 0.5 mg/kg was given once and calcium declined to 12.8 mg/dL 12 hours later. The infant was kept on a low calcium diet for a few months with no subsequent hypercalcemia. Conclusion: SCFN is a potentially life-threatening complication due to development of unrecognized hypercalcemia. A single dose of bisphosphonate can be optimal for treatment of hypercalcemia. Abbreviations: 1,25-(OH)2D 1,25-dihydroxyvitamin D; 25-OHD 25-hydroxyvitamin D; HIE hypoxic ischemic encephalopathy; PTH parathyroid hormone; SCFN subcutaneous fat necrosis