Necrotising fascitis

Question 1

Differnetial diagnosis

Answer 1

Cellulitis
Necrotizing fasciitis
Trauma/haematoma (systemic symptoms make this less likely)
Myositis
Osteomyelitis
DVT (unlikely in an active young man)
Abscess (?IVDU)
(Erythema Nodosum- Nodules. Underlying autoimmune disease, TB, EBV etc).

Question 2

First line investigations

Answer 2

FBC
U+E
Lactate
CRP
ESR
Doppler ultrasound of leg
Blood Cultures

Mark area of erythema and closely monitored overnight

Question 3

Inital abx prophylaxis

Answer 3

IV fluxcloacillin and benzylpenicillin

LMWH

Note stop NSAIDs

Question 4

Classess of necrotising fascitis

Answer 4

Type I- Synergistic infection with anaerobes (e.g. bacteroides, peptostreptococcus) and aerobes (streptococci, enterobacteriaciae). More common in elderly diabetic patients. This is why very broad antibiotic cover is required.

Type II- Infection with Group A Streptococci (S. pyogenes or occasionally S.aureus), mediated by toxin production.

(Type III- Vibrio vulnificus- after trauma in sea water).

(Type IV- Fungal).

Question 5

Next management

Answer 5

urgent!!!! Surgical/Plastics/Orthopaedics review (who to call may depend on the hospital), for wide debridement of all the infected tissue.

Iv abx are important at this stage, 
"BJs makes craig get frisky" 
- IV benzylpeniciilin (for strep) 
-IV metronidazole (for anaerobes) 
-PO/IV clinidmycin (ffor anoerobes) 
-IV gentamicin 
-IV Flucloaxicillin 

5 days post op
Fluids rapidly, and catherter