The Laboratory Risk Indicator for Necrotizing Fasciitis score for discernment of necrotizing fasciitis originated from Vibrio vulnificus infections

Abstract

Background: The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score has been verified as a useful diagnostic tool for detecting necrotizing fasciitis (NF). Its application, however, is mainly for NF types I and II. The practical relevance of the LRINEC score for Vibro vulnificus-related skin and soft tissue infection (SSTI) was hardly ever investigated. The aim of this study was to assess the applicability of the LRINEC scoring system and to identify NF-predicting factors in patients with V. vulnificus-caused SSTI.

Methods: A retrospective study was conducted, enrolling 125 consecutive patients diagnosed with V. vulnificus-related SSTI who were admitted to a teaching hospital between January 2003 and December 2011. Demographics, laboratory data, comorbidities, treatment, and outcomes were collected for each patient and extracted for analysis. Logistic regression and receiver operating characteristic curve analyses were performed.

Results: The mean (SD) age of the 125 patients was 63.0 (10.9) years; 58% of the patients were male. The mean (SD) LRINEC score at admission was 2.4 (1.9) points. Of the 125 patents, 72 (58%) had NF. Multivariate analysis revealed that the presence of hemorrhagic bullous lesions (p = 0.002) and higher LRINEC scores at admission (p < 0.0001) were significantly associated with the presence of NF. In addition, the area under the receiver operating characteristic curve for the LRINEC scoring model for detecting NF was 0.783 (p < 0.0001). An optimal cutoff LRINEC score of 2 or greater had a sensitivity of 71%, a specificity of 83%, and a positive predictive value of 85%, with an 11.9-fold increased risk for the presence of NF (p < 0.0001).

Conclusion: We have demonstrated that the LRINEC score and hemorrhagic bullous/blistering lesions are significant predictors of NF in patients with V. vulnificus-related SSTI. V. vulnificus-infected patients having hemorrhagic bullous/blistering lesions or with an LRINEC score of 2 or greater should be thoughtfully evaluated for the presence of NF.

Level of evidence: Diagnostic test study, level II.