SUBCUTANEOUS FAT NECROSIS OF THE NEWBORN

Subcutaneous fat necrosis of the newborn: A systematic review of surgical management and outcomes

BACKGROUND

Subcutaneous fat necrosis of the newborn (SCFN) is a rare form of panniculitis manifesting as erythematous plaques or nodules at sites of brown fat in neonates. Surgical management may be indicated in severe cases; however, there is a paucity of literature compiling presentations and outcomes of these surgical patients.

METHODS

The authors performed a systematic review, in consultation with a licensed librarian, on MEDLINE and Embase for studies including patients with SCFN who were surgically managed.

RESULTS

The search strategy generated 705 results, among which 213 (30.2%) were excluded for lack of discussion on surgical management. Twenty-two studies discussed surgical management of SCFN in 26 patients, but in 6 of these studies the patients were not surgically managed. Ultimately, 16 articles with 16 patients who were surgically managed were included in the study. Average age at diagnosis was 11.8 ± 9.8 days; average age at surgery was 39.5 ± 70.4 days. The most common etiologies were "unknown" (6, 37.5%), therapeutic hypothermia (4, 25.0%), and birth complications (4, 25.0%). Patients harbored nodules on the back (14, 87.5%), upper extremities (7, 43.8%), lower extremities (7, 43.8%), buttocks (5, 31.3%), and head or neck (3, 18.8%). Linear regression models revealed the presence of back lesions and predicted concomitant medical complications (β = 2.71, p = 0.021).

CONCLUSIONS

Patients undergoing surgical management for SCFN most commonly harbor lesions on the back and extremities that are secondary to therapeutic hypothermia or of unknown origin. Reporting of additional cases is needed to further elucidate surgical management and outcomes.

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.

Surgical management of subcutaneous fat necrosis of the newborn required due to a lack of improvement: a very rare case

Subcutaneous fat necrosis of the newborn (ScFN) is an uncommon and transient disease characterized by defined areas of fat necrosis and overlying cutaneous nodule lesions. It usually becomes apparent within the first 6 weeks of life in full-term or post-term infants. It is caused by generalized and/or local tissue hypoperfusion. The skin lesions of ScFN tend generally to improve spontaneously in a few weeks. We present a full-term newborn with birth distress. After therapeutic hypothermia, she presented voluminous and numerous subcutaneous fat necrosis with extensive calcifications. Surgical management was decided at her ninth month because of a total lack of regression. Hypercalcaemia, the most threatening complication, appeared only after this delayed surgery.