Hypercalcemia in children and adolescents

Abstract

Purpose of the review-In this review we define hypercalcemia levels, common etiologies for hypercalcemia in children, and treatment in order to aid the practicing pediatrician.Recent Findings-One rare cause of hypercalcemia in the child is Familial hypocalciuric hypercalcemia (FHH) [also termed familial benign hypercalcemia (FBH)]. Mutations that inactivate the Ca 2+ -sensing receptor gene FHH have been described as an autosomal dominant disorder, but recently milder mutations in the CASR have been shown to cause hypercalcemia when homozygous.Summary-Normal serum levels of calcium are maintained through the interplay of parathyroid, renal, and skeletal factors. In this review, we have distinguished the neonate and infant from the older child and adolescent because the causes and clinical features of hypercalcemia can differ in these two age groups. However the initial approach to the medical treatment of severe or symptomatic hypercalcemia is to increase the urinary excretion of calcium in both groups. In most cases, hypercalcemia is due osteoclastic bone resorption, and agents that inhibit or destroy osteoclasts are therefore effective treatments. Parathyroid surgery, the conventional treatment for adults with symptomatic primary hyperparathyroidism, is recommended for all children with primary hyperparathyroidism.

Vitamin D Toxicity in an Infant: Case Files of the University of California, San Francisco Medical Toxicology Fellowship

“…High calcium intake rarely results in hypercalcemia in the adult and usually occurs in patient with concomitant chronic kidney disease and a significant decrease in calcium excretion. In contrast, in the small infant, hypercalcemia can occur with ingestion of calcium-enriched formulas [4].…”

“…The vitamin D supplement purchased online was a concentrated form containing 400 IU per drop. A previously published report of a similar vitamin D overdose [4] demonstrated that 1 mL was equivalent to approximately 30 drops; the patient was therefore receiving roughly 30 times the intended daily dose of vitamin D (12,000 IU per day) for approximately 1 month. According to the Institute of Medicine, the level above which there is risk for adverse events in the neonate (0-6 months of age) is 1,000 IU per day [6].…”

“…The remaining 2 % circulates in the blood. Plasma calcium levels are maintained by the interplay between tubular reabsorption in the kidneys, absorption from the small intestine, and bone remodeling [4]. Maintenance of normal calcium levels is under tight regulation by parathyroid hormone (PTH) and vitamin D. PTH is secreted by the parathyroid glands and increases serum calcium by direct action on osteoclasts in bone, and by activation of vitamin D in the kidney.…”

“…Rigorous hydration with 0.9 % saline alone is often an effective treatment. A loop diuretic such as furosemide is rarely necessary and can increase the risk of excessive diuresis and dehydration, as well as the development nephrocalcinosis [4].…”

“…These agents can lower serum and urinary calcium levels in patients with hypercalcemia due to a variety of causes and the effects can last for weeks. Patients must be monitored carefully however, as these agents may result in hypocalcemia, hypophosphatemia, and hypomagnesemia and comprehensive clinical trials on the safety and efficacy of these agents in children are lacking [4].…”