Follow-up during early infancy of newborns diagnosed with subcutaneous fat necrosis

Subcutaneous fat necrosis of the newborn: A retrospective study of 32 infants and care algorithm

OBJECTIVE

To describe the clinical and laboratory outcomes of infants with subcutaneous fat necrosis of the newborn (SCFN) and propose a care algorithm.

METHODS

This single-center, retrospective study of infants diagnosed with SCFN at Ann & Robert H. Lurie Children's Hospital of Chicago from 2009 to 2019.

RESULTS

Of 32 infants who met inclusion criteria, most were born full-term (84%), born via cesarean section (58%), had normal weight for gestational age (69%), and experienced delivery complications (53%). Twenty-nine infants (91%) had calcium drawn, and all had hypercalcemia. Three infants developed clinical symptoms of hypercalcemia, two required hospital admission, two developed nephrocalcinosis, and one developed acute kidney injury. The majority of infants (62%) had a peak ionized calcium between 1.5 and 1.6 mmol/L. No infants with peak ionized calcium less than 1.5 mmol/L developed complications of hypercalcemia. Most patients were diagnosed with hypercalcemia (86%) and demonstrated peak ionized calcium levels (59%) within the first 28 days of life. No patients developed hypercalcemia after 3 months of age.

CONCLUSION

Hypercalcemia occurred in 100% of infants who had laboratory monitoring. We recommend obtaining an initial ionized calcium level when SCFN is suspected, and monitoring for the first 3 months of life if hypercalcemia has not been detected. In patients with asymptomatic hypercalcemia less than 1.5 mmol/L, there appears to be low likelihood of related complications. For symptomatic, markedly elevated (>1.6 mmol/L), or persistently elevated levels (>6 months) we suggest coordinated care with endocrinology or nephrology, consider hospitalization, and urinary system ultrasound.

Severe hypercalcaemia and acute renal failure in an infant with subcutaneous fat necrosis

Subcutaneous fat necrosis (SFN) in the newborn is a form of panniculitis which presents with erythematous nodules and indurated plaques. Severe life-threatening hypercalcaemia can occur as a late complication. A 2-month-old girl presented with severe hypercalcaemia and acute renal injury as a complication of SFN. She was admitted to hospital with the chief complaint of failure to thrive. She had a history of therapeutic hypothermia. After successful treatment of the hypercalcaemia with bisphosphonates, the acute renal injury recovered spontaneously. In neonates with SFN, acute renal injury is a rare complication of hypercalcaemia. Timely prevention of the complications of hypercalcaemia in SFN is essential.

Extensive subcutaneous fat necrosis complicated by neonatal hypercalcaemia

subcutaneous fat necrosis is a benign and often self-limiting inflammatory disorder experienced by newborns who were exposed to perinatal stress in the form of asphyxia, hypothermia, cord prolapse, and/or sepsis. lesions are usually benign and self-limiting, with complete resolution anticipated within a few weeks up to 6 months. they can be accompanied by multiple complications. of which the most significant and of life-threatening potential is neonatal hypocalcaemia. if not timely anticipated and adequately treated, the patient might deteriorate due to dehydration and acute renal failure. symptoms of neonatal hypercalcaemia can be variable in this age group, transcending from a nonspecific presentation of irritability, poor feeding, vomiting and constipation to the well-recognised polyuria, polydipsia, and dehydration. therapeutic options are provided through initial hyperrehydration and calcium wasting diuretics, switching feeds to a low calcium and vitamin D formula milk, institution of systemic steriods and if necessary, inititating bisphosphonate therapy in hypercalcaemia that is severe, recalcitrant to the previously mentioned treatment modalities, and/or when a rapid decrease in serum calcium levels is desired. in this report we describe a case of a 10 month old female infant with moderate neonatal hypercalcaemia as a complication of extensive SCFN manifestating by the age of 10 days and persisting into a prolonged clinical course of up to 9 months until most of the lesions were resolved.

Brown fat necrosis with calcifications in the newborn: Risk factors, radiographic findings, and clinical course

Objective:

To describe the radiographic appearance of subclinical calcified brown fat necrosis and the associated clinical and laboratory findings.

Materials and Methods:

Picture Archiving and Communications Sytem (PACS) was searched using keywords “soft tissue calcification” and “chest.” The clinical record was searched for prior cardiac surgery, bypass, Extracorporeal Membrane Oxygentation (ECMO) and prostaglandin use. Age when calcifications were first detected, location, resolution, and associated laboratory abnormalities were recorded.

Results:

Nine patients were identified. None had skin lesions. All patients had congenital heart disease and had experienced cardiac/respiratory arrest and/or severe hypotension 1–6 weeks before soft tissue calcifications occurred. Calcifications resolved by 9 weeks to 5 months in 3 patients. The remaining were either deceased or lacked follow-up imaging. Renal ultrasound was performed in all but 1 patient. Nephrocalcinosis was only seen in 1 patient.

Conclusion:

Brown fat necrosis is subclinical, diagnosed on plain film, and likely self-limited. It occurs in term and preterm infants who have undergone significant systemic stress and carries a poor prognosis.

Hypercalcemia, hyperkalemia and supraventricular tachycardia in a patient with subcutaneous fat necrosis

BACKGROUND

Subcutaneous fat necrosis (SCFN) is a rare, self-limiting condition that has been associated with several complications including hypercalcemia.

CASE PRESENTATION

We present the case of a 6-week-old male who presented to his pediatrician with a dime-sized erythematous nodule consistent with SCFN, who was also found to have supraventricular tachycardia (SVT). Laboratory findings revealed hypercalcemia and hyperkalemia. Extensive evaluation for the electrolyte disturbances revealed no other etiology. This case reinforces that SCFN should be considered in newborns with hypercalcemia of unknown etiology. Additionally, this case is the first to suggest a connection between SCFN and hyperkalemia. Electrolyte abnormalities can potentially contribute to arrhythmogenesis and may have triggered the arrhythmia in our patient.

CONCLUSIONS

Our case highlights the importance of remaining vigilant in the workup of atypical rashes of the infant, which should include early assessment of serum electrolytes.

Neutrophil-rich subcutaneous fat necrosis of the newborn: A potential mimic of infection

BACKGROUND

The inflammatory infiltrate seen in biopsy specimens obtained from patients with subcutaneous fat necrosis of the newborn (SCFN) has classically been described as consisting mostly of histiocytes. However, we encountered patients with SCFN whose biopsy specimens revealed mostly neutrophils, prompting infection to be an initial consideration.

OBJECTIVES

We sought to describe cases of SCFN in which neutrophils formed the majority of the infiltrate at our institution and in the literature.

METHODS

We performed a retrospective analysis of patients with SCFN reported at our institution and a literature review of SCFN.

RESULTS

Thirteen cases of SCFN were identified at our institution. In 2 of 13 cases, neutrophils composed >75% of the inflammatory infiltrate, and both lesions were 1 day old. From the literature review, neutrophils were mentioned as a component of the infiltrate in 10 of 124 cases, but in none were neutrophils described as forming the majority of the infiltrate.

LIMITATIONS

This study is limited by its retrospective nature and small sample size.

CONCLUSIONS

Neutrophils can comprise most of the inflammatory cells in patients with SCFN, especially early in the course of the disease. This variant of SCFN can be easily mistaken for infection.