Subcutaneous Fat Necrosis of the Newborn

• Figure 2.1 A: Neonatal pustular melanosis* B: Neonatal cephalic pustulosis (Reprint from Boekhout T, Gueho-Kellerman E, Mayser P, Velegraki A. Malassezia and the Skin. New York, NY: Springer; 2010) C: Subcutaneous fat necrosis* * Reprint from Laxer RM, ed. The Hospital for Sick Children: Atlas of Pediatrics. Philadelphia, PA: Current Medicine; 2005

  Onset within first weeks of life; localized form of sclerema neonatorum in healthy infants
• Presents with indurated subcutaneous nodules favoring cheeks, shoulders, back, buttocks, and thighs
• Associated with hypothermia, perinatal hypoxemia (from preeclampsia, meconium aspiration, etc.), hypoglycemia
• Calcification may occur; ± profound hypercalcemia with resolution, so prudent to monitor calcium levels until 1 month after full resolution of lesions
• Histology: panniculitis with prominent inflammatory infiltrate, needle-shaped clefts and fat necrosis