Objective criteria may assist in distinguishing necrotizing fasciitis from nonnecrotizing soft tissue infection

Background: Optimal treatment of necrotizing fasciitis (NF) requires rapid diagnosis. The purpose of the study was to identify objective admission measurements that help differentiate NF from nonnecrotizing (non-NF) infection and, among NF patients, to identify admission factors that predict mortality. Methods: Twenty-one NF cases were paired with matched non-NF controls. Statistical comparison of admission vital signs, laboratory values, and radiographic studies was performed. Results: On multivariate analysis, admission white blood cell count (WBC) >14 × 109/L, serum sodium <135 mmol/L, and blood urea nitrogen (BUN) >15 mg/dL separated NF from non-NF patients. Mortality for NF patients was predicted by admission WBC >30 × 109/L. Mortality was also significantly increased for patients transferred from an outside institution prior to definitive therapy. Conclusions: Objective admission criteria (elevated WBC and BUN and decreased serum sodium) can assist in distinguishing NF from non-NF infections. The best objective predictor of mortality in NF patients is marked elevation of admission WBC.