Clinical assessment and risk stratification
It requires a high index of clinical suspicion due to the non-specific early signs and symptoms, and its rapidly progressive nature.
Consideration of any risk factors listed below may help to point towards the diagnosis:
Risk Factors3,12
- Age >50
- IV drug use
- Malnutrition
- Chronic renal or liver disease
- Obesity
- Diabetes
- Immunosuppression (including steroid use)
- Skin injury – insect bites, trauma, surgical wounds
- Malignancy
- Peripheral vascular disease
Clinical Features2,3,5
| Early Signs | Local erythema or a tense, ‘shiny’ swollen area
Pain out of proportion to clinical findings – severe and constant Fever Malaise or flu-like symptoms |
| Late Signs | Tense oedema – ‘woody’ feel to skinBullae
Dusky blue/purple discolouration Crepitus/surgical emphysema Systemic features such as hypotension/septic shock and other signs of multi organ dysfunction e.g. confusion, anuria etc. |
Learning Bite
Necrotising fasciitis is difficult to diagnose early due to the non-specific nature of its early features. It is often misdiagnosed for cellulitis and requires a high index of suspicion to identify. Consider cover for necrotising fasciitis in those patients who are more unwell with cellulitis than you would ordinarily expect, those with pain out of proportion to their clinical findings and those failing to respond to treatment!