Differential Diagnosis of Hypercalcemia in Neonates
Single Most Likely Diagnosis
- Subcutaneous Fat Necrosis: This condition is a common cause of hypercalcemia in neonates, particularly in those who have experienced perinatal distress or have been exposed to cold stress. It leads to the release of calcium from necrotic fat tissue.
Other Likely Diagnoses
- Vitamin D Intoxication: Excessive intake of vitamin D by the mother or the neonate can cause hypercalcemia due to increased absorption of calcium from the gut.
- Hypophosphatasia: A rare genetic disorder characterized by low alkaline phosphatase activity, leading to impaired bone mineralization and hypercalcemia.
- Familial Hypocalciuric Hypercalcemia (FHH): An autosomal dominant disorder caused by mutations in the calcium-sensing receptor gene, leading to inappropriate parathyroid hormone secretion and hypercalcemia.
Do Not Miss Diagnoses
- Hyperparathyroidism: Although rare in neonates, primary hyperparathyroidism due to parathyroid gland hyperplasia or adenoma can cause severe hypercalcemia and must be considered to avoid missing a potentially life-threatening condition.
- Malignancy: Although extremely rare in neonates, certain malignancies like parathyroid gland carcinoma or other tumors producing parathyroid hormone-related protein can cause hypercalcemia.
Rare Diagnoses
- Williams Syndrome: A genetic disorder characterized by elfin facies, intellectual disability, and congenital heart disease, which can also present with hypercalcemia due to abnormal vitamin D metabolism.
- Jansen's Metaphyseal Chondrodysplasia: A rare genetic disorder causing hypercalcemia due to constitutive activation of the parathyroid hormone receptor.
- Blue Diaper Syndrome: A rare condition characterized by hypercalcemia, nephrocalcinosis, and idiopathic hypercalcemia, often presenting with a blue discoloration of the diaper due to calcium phosphate crystals.