Clinical Characteristics of Necrotizing Soft Tissue Infection Among Patients with High LRINEC Scores

The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is a widely used adjunctive diagnostic tool for necrotizing soft tissue infection (NSTI). However, patients with high LRINEC scores do not uniformly have NSTI and often represent a diagnostic gray zone requiring urgent differentiation from other severe soft tissue infections. This study aimed to clarify the clinical characteristics of NSTI among patients with high LRINEC scores.

We retrospectively reviewed patients hospitalized for severe soft tissue infections with sepsis between January 2014 and December 2023 with LRINEC scores ≥6, classified as NSTI (n = 11) or non-NSTI (n = 9). Non-NSTI cases were limited to severe cellulitis with bacteremia requiring intensive care. Clinical findings, laboratory parameters, imaging findings, and vasopressor use within 24 hours after hospital arrival were compared.

Patients with LRINEC had significantly higher white blood cell counts and serum creatinine levels. Fluid collection along the fascia and gas formation on CT were more frequent in the NSTI group. Mean blood pressure at presentation did not differ between groups; however, vasopressor use within 24 hours after hospital arrival was significantly more common in the NSTI group, suggesting early hemodynamic deterioration or greater disease severity CONCLUSIONS: In patients with high LRINEC scores, NSTI was associated with marked inflammatory response, renal dysfunction, specific CT findings and early hemodynamic instability. Early vasopressor requirement should be interpreted primarily as a marker of early hemodynamic deterioration or disease severity, rather than a diagnostic characteristic specific to NSTI.