Calcium management challenges in a macrosomic child with subcutaneous fat necrosis

Abstract

We present a case that illustrates the fluctuations in calcium levels to be expected while managing an infant with maternal gestational diabetes mellitus who also develops subcutaneous fat necrosis (SCFN). There is initial hypocalcaemia due to functional hypoparathyroidism, requiring judicious calcium replacement. But with increased extrarenal production of 1,25-dihydroxyvitamin D due to granulomatous inflammation of subcutaneous adipose tissue, hypercalcaemia ensues. With a self-limiting course, SCFN of the newborn has an excellent prognosis and resolves spontaneously. However, aberrations in serum calcium levels can manifest in life-threatening complications and must hence be closely monitored.

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

“…Typical skin lesions consist of firm, erythematous, or purplish indurated plaques which evolve to subcutaneous hard painful nodules on the back, shoulders and upper limbs, and thighs. Diagnosis is essentially clinical, 9 although a skin biopsy may be useful in case of clinical doubt 4 . Differential diagnosis for SCFN may be difficult and includes sclerema neonatorum and cellulitis 1,2,4 …”

“…Several predisposing factors for SCFN have been identified, which include maternal risk factors (preeclampsia, gestational diabetes, drug consumption) or neonatal conditions such as traumatic delivery, asphyxia, meconium aspiration, macrosomia, or septic shock 2,9 . As published in some systematic reviews, almost 90% of patients experienced pregnancy complications and many were delivered via cesarian section due to fetal distress 4 .…”

“…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 …”

Congenital liquified subcutaneous fat necrosis in a newborn: an unusual case

“…Lesions are mostly located on the posterior trunk, thighs, proximal extremities, and cheeks. Spontaneous resolution without sequelae is the rule; it may take weeks to months [1,2]. Unusually, we can have liquefaction or ulceration of nodules [3].…”

“…Diagnosis is essentially clinical [1]. Some entities in the differential diagnosis may be difficult to exclude initially, or include cellulitis and sclerema neonatorum [2]. We describe a case of a newborn with subcutaneous fat necrosis who developed a liquefaction, for whom a surgical incision was performed.…”