The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score is a tool to distinguish ordinary skin infections from necrotizing fasciitis.
Mnemonic: NeC WASH
Na level:
- <135 mmol/L: 2 points
Creatinine:
- >1.6 mg/dl: 2 points
WBC:
- <15,000/cu.mm: 0 points
- 15,000-25000/cu.mm: 1 point
- >25,000/cu.mm: 2 points
Acute phase reactant (CRP):
- >/= 150: 4 points
Sugar:
- >180 mg/dl (10 mmol/l): 1 point
Hemoglobin:
- >13.5 g/dl: 0
- 11-13.5 g/dl: 1
- <11 g/dl: 2
Remember: All variables have maximum score of 2 except CRP (max. 4) and blood glucose (max. 1). Maximum total score is 13.
Interpretation:
A LRINEC score, a score ≥ 6 is a reasonable cut-off to rule in necrotizing fasciitis, but a LRINEC < 6 does not completely rule out the diagnosis. A score > 6 has PPV of 92% and NPV of 96% for necrotizing fasciitis.
Reference: Wong C. “The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections”. Crit Care Med. 2004. 32(7):1535-41.