Explanation:
The LRINEC score is a validated tool to help distinguish necrotizing fasciitis from severe cellulitis or abscess. It incorporates six routine laboratory values: CRP, WBC count, hemoglobin, serum sodium, serum creatinine, and serum glucose. Hyponatremia (Serum sodium < 135 mmol/L) is a critical component, scoring 2 points, and reflects profound systemic toxicity, fluid shifts, and the systemic inflammatory response syndrome (SIRS). A total score of 6 or higher raises strong clinical suspicion for necrotizing fasciitis. Reference: Miller's Review of Orthopaedics, 8th Edition.