Necrotising fasciitis

Headline
Etiology Rapidly spreading infectious along fascial planes. Pathogen: Type I: polymicrobial. Type II: Strep pyogenes, Staph aureus. In perineum/groin: Fournier's gangrene.
Epidemiology Risk factors: relatively minor trauma/surgery or blunt trauma causing "seeding"; immunocompromise (including T2DM)

Klebsiella - associated with travel to Taiwan (!)
Clinical presentation - Commonly present after being unwell for a few days
- fever, pain out of proportion to findings (↓ swelling/redness); anaesthesia over affected area over 24-48 hours
- LATE: haemorrhagic blisters, bruising, necrosis - DO NOT rely on these to make diagnosis
Pathogenesis - superantigen toxins
- enzymes which digest the fascia
Diagnostic investigations
Management Resuscitation as with sepsis
Debridement
Probably Level 2-3 care
Example of empirical abx: taz/meropenem/ceftriaxone + vanc/linezolid + clindamycin

LRINEC score

  • CRP >150 = +4
  • WCC 15-25 +1; >25 +2
  • Hb 110-135 +1; <110 +2
  • Na <135 +2
  • Crt >141 +2
  • glucose >10 +1
    Each item is individually predictive, but score = 6 unctions as a diagnostic test for necrotizing fasciitis with a sensitivity of 89.9% and a specificity of 96.9%.