Necrotizing fasciitis following venomous snakebites in a tertiary hospital of southwest Taiwan.

BACKGROUND: Necrotizing fasciitis following venomous snakebites is uncommon. The purpose of this study was to describe the initial clinical features of necrotizing fasciitis after snakebites, and to identify the risk factors for patients with cellulitis who later developed necrotizing fasciitis.

METHODS: Sixteen patients with surgically confirmed necrotizing fasciitis and 25 patients diagnosed with cellulitis following snakebites were retrospectively reviewed over a 6-year period. Differences in patient characteristics, clinical presentations, snake species and laboratory data were compared between the necrotizing fasciitis and the cellulitis groups.

RESULTS: None of the 41 patients died after being bitten by a snake. Twenty-nine patients (70.7%) were bitten by a cobra. Enterococcus species and Morganella morganii were the most common pathogens identified in wound cultures. Relative to the cellulitis group, the necrotizing fasciitis group had significantly higher rates of hemorrhagic bullae (p=0.000), patients with underlying chronic disease (p=0.019), white blood cell counts (p=0.035), segmented white cell counts (p=0.02), and days of hospitalization (p=0.001).

CONCLUSIONS: Victims of venomous snakebites should be admitted for close monitoring of secondary wound infections. The risk factors of developing necrotizing fasciitis from cellulitis following snakebites were associated with chronic underlying diseases and leukocytosis (total white blood-cell counts ≥10000cells/mm3 and ≥80% of segmented leukocyte forms). Physicians should be alert to a worsening wound condition after a snakebite, and surgical interventions should be performed for established necrotizing fasciitis with the empirical use of third-generation cephalosporins plus other regimens.