ESPE Abstracts

Introduction: Subcutaneous fat necrosis of the newborn (SCFN) is a self-limiting panniculitis which can develop in the first weeks of life. The disorder is characterized by firm, red or purple subcutaneous nodules and plaques on the trunk, buttocks, cheeks, and extremities and is associated with perinatal stress. SCFN may lead to hypoglycemia, anemia, thrombocytopenia, hypertriglyceridemia and hypercalcemia. The proposed mechanism for the hypercalcemia is extrarenal 1,25-di-OH-vitamine D formation due to expression of 1α-hydroxylase in the inflammatory infiltrate of the subcutaneous adipose tissue.

Case description: We present a female neonate who suffered from perinatal asphyxia due to a complicated delivery. She quickly recovered and was dismissed after one week. She was re-admitted to the neonatology department after another week with poor feeding, weight loss and lethargy. Clinical examination showed no abnormalities except for a subtle slightly firm swelling (2x2cm) on the back without discoloration of the skin. Laboratory evaluation showed an elevated calcium ion [2.34 mmol/l (ref. 1.15-1.33)], and 1,25-di-OH-vitamin D3 [586 pmol/L (ref. 59-159)] level. Parathyroid hormone level was suppressed, phosphate and 25-OH-vitamin D values were normal. Electrocardiogram was normal. Ultrasound of the kidneys showed nefrocalcinosis. Ultrasound of the skin revealed subcutaneous fat necrosis. The diagnosis of subcutaneous fat necrosis with hypercalcemia was made. Initial treatment with hyperhydration, low-calcium diet for the mother and discontinuation of vitamin D suppletion did not decrease the calcium ion level. A gift of pamidronate i.v. was given for the long-term lowering of calcium ion levels which resulted in hypomagnesemia, hypokalemia, and hypophosphatemia. Also hypertriglyceridemia, hypoalbuminemia and an increased lactate level were present. For acute lowering of the calcium ion level a gift of furosemide i.v. and calcitonin s.c. were given. On the third day breast milk was replaced with low-calcium formula. A week after presentation more subtle skin lesions appeared. In total, 2 gifts of pamidronate and 9 gifts of calcitonin in a period of 14 days were necessary to decrease and maintain the calcium ion level within normal values.

Discussion: Despite only very subtle skin lesions severe hypercalcemia developed in our patient with SCFN after mild perinatal asphyxia. The tachyphylaxis which is observed by others after 24-48 hours of successive doses of calcitonin did not occur in our patient. This case report adds to the relatively scarce available literature on the metabolic changes which can occur in patients with SCFN and the effective treatment of the associated hypercalcemia.