Background
Necrotizing Fasciitis is a life-threatening bacterial soft tissue infection that spreads along soft tissue planes rapidly.
Diagnosis is made clinically with the presence of skin discoloration, bullae, palpable crepitus and calculation of the LRINEC score.
Emergent frozen section can help confirm diagnosis in early cases.
Treatment is emergent radical debridement of all devitalized tissues with broad-spectrum IV antibiotics.
Risk factors
- Immune suppression
- Diabetes
- AIDS
- Cancer
- Obesity
- Bacterial introduction
- IV drug use
- Hypodermic therapeutic injections
- Insect bites
- Skin abrasions
- Abdominal & perineal surgery
Clinical
Symptoms
Early
- Localized abscess or cellulitis with rapid progression
- Minimal swelling, trauma or discoloration
Late
- Severe pain
- High fever, rigors
- Tachycardia
Signs
- Skin bullae
- Discoloration
- Ischemic patches
- Cutaneous gangrene
- Swelling / oedema
- Induration and erythema
- Subcutaneous emphysema (gas producing organisms)
Imaging
- X-rays not required for Dx
DDx
- Gas gangrene
Management
Initial
- Prompt resuscitation and haemodynamic monitoring
- Early broad spectrum antibiotics (please see NCHD.ie for details)
- Pip-Tazobactam 4.5g q6h iv
- plus
- Clindamycin 1.2g q6h iv
- plus
- Metronidazole 500mg q8h iv
- Please contact Micro
- Immediate surgical debridement
- Consider hyperbaric O2 chamber if anaerobic organism suspected
Surgical
- Emergency radical debridement
- Whenever suspicion for necrotizing fasciitis
- ± amputation
- Findings may include:
- Liquefied subcutaneous fat
- Muscle necrosis
- Pus
- Tissue thrombosis
Grading
| Detail | Score |
|---|---|
| Inflam. markers | |
| CRP (mg/L) ≥150 : | 4 |
| WBC count (×103/mm3) | |
| &tl;15: | 0 |
| 15–25: | 1 |
| >25: | 2 |
| Haemoglobin (g/dL) | |
| >13.5: | 0 |
| 11–13.5: | 1 |
| <11: | 2 |
| Renal/metabolic | |
| Serum Na+ <135mmol/L: | 2 |
| Creatinine >141 µmol/L: | 2 points |
| Serum glucose >10 mmol/L: | 1 |
Prognosis
- Mortality rate 32% correlates time to surgical intervention