Symptomatic hypercalcemia in the first months of life: calcium-regulating hormones and treatment.

Neonatal hypercalcemia is a rare condition often of unclear pathogenesis. If unrecognized and untreated it may result in central nervous system and renal damage. We studied three infants with symptomatic neonatal hypercalcemia pointing out pathogenetic and therapeutic aspects. One infant was found to have transient hyperparathyroidism with high intact parathyroid hormone (iPTH) levels. One infant had an incomplete form of Williams syndrome with hypercalcemia and an elfin facies. The pathogenesis is unclear in this case. A reduced secretion of calcitonin or an hypersensitivity to vitamin D might be the underlying defect. The third case was found to have subcutaneous fat necrosis and hypercalcemia associated with high 1,25(OH)2D levels and suppressed iPTH levels. These findings suggest an unregulated extrarenal 1,25(OH)2D production. These infants were treated with hydratation, furosemide, corticosteroids and low calcium diet. Symptomatic neonatal hypercalcemia should be treated promptly. However blood has to be taken before starting treatment to study calcium-regulating hormones and clarify pathogenesis.