Retroperitoneal necrotizing fasciitis in a 4-year-old girl.

Necrotizing fasciitis is a rare but serious condition with a poor prognosis both in adults and in children. Retroperitoneal localization is mostly associated with fatal outcome. Early diagnosis, extensive and repeated surgical debridement, and use of antibiotics are necessary. Herein the authors report on a 4-year-old girl in whom retroperitoneal necrotizing fasciitis developed after she suffered from pyelonephritis. In this case, the outcome was favorable because of early surgical intervention, confirming the diagnosis.