diagnostic scoring system for necrotising fasciitis

Last reviewed 01/2018

Laboratory Risk Indicator for Necrotizing Fasciitis scoring system (LRNEC) is considered to be the most accurate diagnostic scoring system currently in use (1). It is used to differentiate NF from other type of soft tissue infection based on the laboratory investigations

  • a score of
    • 5 points-indicates a low risk (<50% probability) of NF
    • 6-7 points-indicate and intermediate risk (50%-75% probability)
    • 8 points or more - indicate a high risk (>75% probability) (2)
  • in a Singaporean population, a score of ≥6 was 93% sensitive and 92% specific for necrotising fasciitis while in UK it was  only 74% sensitive and 81% specific.

variable

score

C reactive protein (mg/L)

 

>150

4

white blood cell count (per mm3)

 

<15

0

15-25

1

>25

 

haemoglobin (g/dL)

 

>13.5

0

11-13.5

1

<11

2

sodium (mmol/L)

 

<135

2

creatinine

 

>141

2

glucose (mmol/L)

 

>10

1

Reference: