Distinguishing early necrotizing fasciitis from severe cellulitis is difficult. In 2004, Wong et al proposed the LRINEC(Laboratory Risk Indicator for Necrotizing Fasciitis) score as a means to distinguish necrotizing fasciitis from other soft tissue infections.
The LRINEC Score
| C-reactive protein (mg/L) | |
| <150 (or <1.5 mg/dL) | 0 |
| ≥150 (or ≥1.5 mg/dL) | 4 |
| Total white blood cell count (per mm3) | |
| <15 | 0 |
| 15–25 | 1 |
| >25 | 2 |
| Hemoglobin (g/dL) | |
| >13.5 | 0 |
| 11–13.5 | 1 |
| <11 | 2 |
| Sodium (mmol/L) | |
| ≥135 | 0 |
| <135 | 2 |
| Creatinine (μmol/L) | |
| ≤141 (or ≤1.6 mg/dL) | 0 |
| >141 (or >1.6 mg/dL) | 2 |
| Glucose (mmol/L) | |
| ≤10 | 0 |
| >10 | 1 |
LRINEC = Laboratory Risk Indicator for Necrotizing fasciitis.
≥6 on the LRINEC score is strongly concerning for necrotizing fasciitis.
Although initial findings seemed promising, subsequent studies have shown that it may not be as accurate in distinguishing necrotizing fasciitis as previously hoped. Therefore, necrotizing fasciitis remains a clinical diagnosis.
Bottom line: Don’t rely on the LRINEC score but rather let history and physical exam guide you to identifying necrotizing fasciitis early. You can support your clinical suspicion with a positive LRINEC score but don’t let a negative score provide false reassurance.
References:
C.H. Wong, L.W. Khin, S.K. Heng, K.C. Tan, C.O. Low. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Crit Care Med, 32 (2004), pp. 1535–1541.
Y.H. Tsai, R.W. Hsu, K.C. Huang, T.J. Huang. Laboratory indicators for early detection and surgical treatment of vibrio necrotizing fasciitis. Clin Orthop Relat Res, 468 (2010), pp. 2230–2237
M.J. Holland. Application of the Laboratory Risk Indicator in Necrotising Fasciitis (LRINEC) score to patients in a tropical tertiary referral centre. Anaesth Intensive Care, 37 (2009), pp. 588–592.
Wilson MP, Schneir AB. A case of necrotizing fasciitis with a LRINEC score of zero: clinical suspicion should trump scoring systems. J Emerg Med. 2013 May;44(5):928-31. doi: 10.1016/j.jemermed.2012.09.039. Epub 2012 Dec 31.
