Definition
Infection of skin and subcutaneous tissue
- spreads across fascial planes
- many microbes can be responsible
Types
Type 1 Polymicrobial
Type 2 Monomicrobial
Aetiology
Group A Beta Hemolytic Strep (S. pyogenes)
- most common cause monomicrobial
S. Aureus / MRSA
Vibrio
- wound contaminated with saltwater
Clostridium
Anaerobes
Predisposing factors
Trauma
- insect bite
- skin laceration
- needle injection
- IVDU
Post operative
Diabetes
Clinical
History of trauma / surgery / IVDU
Pain out of proportion
Skin
- initially swollen and red
- superficial nerves destroyed / skin anaesthetic
- becomes necrotic
Patient febrile and unwell / septic / in shock
- high temperatures
- altered levels of consciousness
MRI
Can distinguish between cellulitis and necrotising fasciitis
- increased T2 signal along fascia
Management
High index clinical suspicion
Surgery
Debridement of infected skin and subcutaneous tissue
- tissue and fluid sent for immediate MCS
- exclude myonecrosis
Antibiotics
Broad spectrum
- penicillin / vancomycin
Hyperbaric Oxygen
Skin cover
- becomes late problem
- patient may need extensive skin flaps
Prognosis
Mortality rates up to 25%