Subcutaneous fat necrosis of the newborn: clinical and histopathological review and use of cutaneous ultrasound Necrosis grasa subcutánea del recién nacido: revisión clínica e histopatológica y utilidad de la ecografía cutánea.

Subcutaneous fat necrosis of the newborn is a rare lobular panniculitis. It is characteristic of term or post-term neonates with a history of perinatal compromise or maternal gestational pathology. The cutaneous manifestations consist of erythematous and indurated subcutaneous plaques and nodules located over the dorsal region and the shoulders. Diagnosis is clinical and pathological. Histopathological findings include lobular panniculitis with a lymphohistiocytic inflammatory infiltrate with few neutrophils, fatty necrosis, deposition of radial needle-shaped crystals in the adipocytes, and possible calcification and hemorrhage. The cutaneous ultrasound shows hyperechoic and avascular subcutaneous cellular tissue and acoustic shadows may appear corresponding to calcifications. The clinical differential diagnosis includes sclerema neonatorum and post-corticosteroid panniculitis. Histologically crystal-forming panniculitis conditions are in the differential diagnosis. The disease is usually self-limited but complications such as hypercalcemia, hypoglycemia, hypertriglyceridemia, thrombocytopenia, and anemia may occur. Complications should be ruled out and treated at diagnosis and during follow-up. The most important complication is hypercalcemia.La necrosis grasa subcutánea neonatal es una paniculitis lobulillar infrecuente. Es característica de neonatos a término o postérmino con antecedentes de sufrimiento perinatal o patología gestacional materna. Las manifestaciones cutáneas consisten en placas y nódulos subcutáneos eritematosos e indurados localizados preferentemente en la región dorsal y los hombros. El diagnóstico es clínicopatológico. Los hallazgos histopatológicos comprenden una paniculitis lobulillar con un infiltrado inflamatorio linfohistiocitario con escasos neutrófilos, necrosis grasa, depósito de cristales radiados en los adipocitos y posibles focos de calcificación y hemorragia. En la ecografía cutánea se observa hiperecogenicidad y avascularización del tejido celular subcutáneo y pueden aparecer sombras acústicas posteriores que se correspondencon calcificaciones. El diagnóstico diferencial clínico se debe realizar con el escleredema neonatorum y la paniculitis postesteroidea, e histológicamente con las paniculitis con formación de cristales. La enfermedad suele ser autolimitada pero pueden aparecer complicaciones como la hipercalcemia, la hipoglucemia, la hipertrigliceridemia, latrombocitopenia y la anemia. Las complicaciones deben ser descartadas y tratadas en el diagnóstico y durante el seguimiento. La complicación másimportante es la hipercalcemia.

Levetiracetam-induced pediatric toxic epidermal necrolysis successfully treated with etanercept.

Successful management of toxic epidermal necrolysis (TEN) with tumor necrosis factor-α inhibitors has been described in adults, but few cases have been reported in children. To date, only four pediatric cases of TEN treated with infliximab and one with etanercept have been published. We present the case of an 8-year-old boy diagnosed with TEN induced by levetiracetam, successfully treated with etanercept, systemic corticosteroids, and intravenous immunoglobulin.