Hypocalcemia Associated with Subcutaneous Fat Necrosis of the Newborn: Case Report and Literature Review

Subcutaneous fat necrosis of the newborn (SCFNN) is a rare benign inflammatory disorder of the adipose tissue but may be complicated by hypercalcemia or less frequently, hypocalcemia, resulting in morbidity and mortality. Here we report the case of a neonate with subcutaneous fat necrosis who surprisingly developed hypocalcemia instead of hypercalcemia. A full-term female neonate was delivered by emergency cesarean section for fetal distress and was subsequently admitted to the Special Care Baby Unit. The mother's pregnancy was uncomplicated up to delivery. Her anthropometric measurements were birth weight 4.1 kg (95^th percentile), length 50 cm (50^th percentile), and head circumference 34.5 cm (50^th percentile). The Apgar scores were 2, 3, and 8 at 1, 5, 10 minutes, respectively. There was no abnormal facies and she was fed with breast milk only. On the seventh day of life, the infant was found to have multiple nodules located in the neck, upper back, and right arm. The nodules were firm, well circumscribed with no evidence of tenderness. Her total serum calcium level was 1.55 mmol/L (normal range 2.2 to 2.7 mmol/L) and this was associated with hypotonia and poor sucking reflex. The packed cell volume was 40%. The serum albumin and blood glucose levels were normal. Her blood culture was sterile. A clinical diagnosis of hypocalcemia associated with SCFNN was made. The infant was treated for hypocalcemia (using calcium gluconate) and was carefully followed-up. The skin lesions resolved completely three months after their eruption. Repeat serum calcium measurements at three, six, and nine months of age were all within normal limits. Although SCFNN is a rare benign clinical condition, it may be complicated by hypocalcemia. Therefore, periodic measurements of the serum calcium levels is warranted in such a patient, beginning from the neonatal period up to the age of six months.