Subcutaneous Fat Necrosis of the Newborn With Initial Hypocalcemia and Familial Recurrence: A Case Report

Abstract

Subcutaneous fat necrosis of the newborn (SFNN) is a rare disorder characterised by indurated plaques or nodules with or without erythema, typically distributed over the cheeks, extremities, posterior trunk, buttocks, and thighs, and appears during the first 2 weeks of life. It is commonly associated with perinatal asphyxia and, while usually self-limited, can lead to severe hypercalcemia. There is no known familial association. The present article describes a neonate with extensive disease, counterintuitive hypocalcemia, and a family history of SFNN and reviews the existing literature on SFNN.

Subcutaneous fat necrosis of the newborn – An atypical case with typical complications

“…Subcutaneous fat necrosis of the newborn is a rare panniculitis usually present in the first weeks of life. The pathogenesis of SFCN remains unclear; however, it has been postulated that perinatal stress may cause hypoxia and hypothermia of the immature fat tissue leading to inflammation and necrosis 2,8 …”

“…Incidence of hypercalcemia varies widely, from 25% to 65%, 4,12 being more frequent in term or full‐term infants and in cases of extensive and truncal skin lesions, according to some reports 2,4,12 . The hypothesized cause of hypercalcemia is that granulomatous inflammatory cells in SCFN express high levels of 1‐alpha‐hydroxylase, the enzyme that converts 25‐OH vitamin D3 to its active form (1,25‐dihydroxyvitamin D3), which can stimulate intestinal calcium uptake 2,7‐9,12 . Hypercalcemia can also be explained by an increased bone resorption in SCFN due to higher prostaglandin E levels, 1,13 and by an increased calcium mobilization from resolving areas of subcutaneous fat necrosis 4 …”

“…Hypercalcemia usually manifests in the first month after the development of the skin lesions, 4 but can occur as late as 6 months afterward; this is why patients should be long‐term monitored 2,12 . Patients with hypercalcemia may be asymptomatic or present with symptoms such as lethargy, irritability, hypotonia, vomiting, polyuria, polydipsia, dehydration, and constipation 7,8,12 . It may lead to severe complications, both acute (cardiac arrest and renal failure), as well as chronic problems (metastatic calcifications) 1,7 .…”

“…There are few cases described in literature about SCFN and hypertriglyceridemia. The pathophysiology of this association is not well established; it may be due to mobilization of fatty acids from the adipose tissue following hypoxia 8 . Clinical significance of this association is not clear either; it can be a sign of an underlying metabolic disease.…”

Subcutaneous fat necrosis of the newborn: clinical and histopathological review and use of cutaneous ultrasound Necrosis grasa subcutánea del recién nacido: revisión clínica e histopatológica y utilidad de la ecografía cutánea

“…La necrosis grasa subcutánea del recién nacido suele presentarse en neonatos a término o postérmino con antecedentes de sufrimiento perinatal o patología gestacional materna [3][4]. No se han descrito diferencias entre sexos y etnias [5].…”