LRINEC

LRINEC, or Laboratory Risk Indicator for Necrotizing Fasciitis, is a scoring system intended to help distinguish necrotizing fasciitis (NF) from non-necrotizing soft tissue infections using routine laboratory data. It was developed by Wong and colleagues in 2004. The score draws on six laboratory variables: C-reactive protein (CRP), white blood cell count (WBC), hemoglobin, sodium, creatinine, and glucose.

Points are assigned for each variable according to specific thresholds: CRP <150 mg/L = 0; ≥150 = 4. WBC <15×10^3/μL = 0; 15–25×10^3/μL = 1; >25×10^3/μL = 2. Hemoglobin >13.5 g/dL = 0; 11–13.5 = 1; <11 = 2. Sodium ≥135 mmol/L = 0; <135 = 2. Creatinine ≤1.6 mg/dL = 0; >1.6 = 2. Glucose ≤180 mg/dL = 0; >180 = 1. The total score ranges from 0 to 13, with higher scores indicating greater likelihood of NF. A commonly cited interpretation designates a score of 6 or more as signaling increased risk, and scores of 8 or higher as more strongly suggestive of NF.

LRINEC is intended as an adjunct to clinical assessment and imaging, not a standalone diagnostic test. It may aid triage and expedite surgical consultation but should not delay urgent intervention if clinical suspicion is high. Limitations include variable diagnostic performance across studies; some patients with NF may have low scores, particularly early in disease, limiting sensitivity in certain populations. See also Necrotizing fasciitis.