The Mysterious Case of a Lumpy Newborn

A former resident calls you from her new rotation in the nursery to come and see a neonate with a perplexing dermatologic condition.

2-week-old infant had stressful delivery, including mild hypoxia. Birth weight, 4.5 kg, delivered via C-section. Rash onset has been acute.

Note firm, inflamed, nodules on back that range in color from skin-toned to purple; skin is peeling over most involved areas

Noted over rib cage are several firm violaceous nodular lesions that may reflect a pressure point at the time of delivery.

Clues to Dx: newborn large-for-gestation, stressed at delivery, not septic, feeding well, vitals are normal; no sign of systemic disease.

Differential Dx: Bacterial cellulitis, erysipelas, infantile hemangioma, rhabdomyosarcoma, sclerema neonatorum, subcutaneous fat necrosis.

Answer: Subcutaneous fat necrosis of the newborn (SFNN) is an uncommon disorderPossible risk factors: perinatal asphyxia, meconium aspiration, cord accidents, hypothermia/cold

SFNN is a form of panniculitis; Exact cause unknown. More common factors seen are: fetal stress during delivery, low oxygen levels, cold temperature, C-section, high birth weight, infection.

SFNN nodules may be painful, resolve spontaneously but may last weeks-months. Compications are rare; hypercalcemia most dangerous; after skin lesions have healed; blood calcium should be monitored after skin lesions clear.

Treatment focuses on aggressive management of hypercalcemia if it occurs: increased fluid intake, low calcium milk feeds, furosemide, corticosteroids, bisphosphonates.