Hypercalcemia in children

Abstract

Hypercalcemia is a result of a wide range of hereditary and acquired conditions encountered by general physicians and pediatricians. Calcium participates in several key physiological functions, control of blood coagulation, bone calcification. Calcium homeostasis is tightly regulated by the interplay between absorption from the small intestine and renal tubular reabsorption, bone remodeling, and disposal through the gut and the kidney. These processes are regulated by local and circulating factors. The two main hormones influencing the homeostasis of calcium are PTH and calcitriol. Cancer-associated hypercalcemia and primary hyperparathyroidism are the most frequent causes of hypercalcemia in adults. In neonates and infants, one should look first at genetic and iatrogenic etiologies. The clinical manifestations of hypercalcemia in children are nonspecific due to damage to various organs and systems and depend on the degree of blood calcium level. Mild hypercalcemia is asymptomatic and often discovered during routine blood work. Moderate and severe hypercalcemia may cause cardiac arrhythmias, affect the nervous system. The differential diagnosis of the possible etiologies of hypercalcemia should start with the assessment of serum parathyroid hormone (PTH) concentration. The causes of hypercalcemia can be divided between PTH-mediated and non-PTH-mediated. Identification of the main causes of hypercalcemia contributes to the timely elimination of trigger factors, beginning of treatment, correction of nutrition and lifestyle. The article highlights physiological mechanisms of calcium homeostasis, clinical manifestations, diagnostic algorithms and treatment of hypercalcemia in children.