Necrotising Fascitis

Question 1

Causes of NF?

Answer 1

Monomicrobial pathogens:
  Group A Streptococcus pyogenes 
  Clostridium perfringens (gas gangrene) and other 
  Clostridial species
  Staph aureus
  Vibrio vulnificans
  Aeronomonas hydrophila
  Polymicrobial pathogens

mixed aerobe-anaerobe bacterial flora
E.coli
Bacteroides fragillis
Strep and Staph

(ref: LIFTFL)

Question 2

What is it?

Where can it occur?

Answer 2

1/ severe bacterial soft tissue infection –> oedema and necrosis of subcutaneous tissue, fascia involved.

can resemble cellulitis –> pt more sick and it’s progressive

2/ 50% in the extremities, remainder = concentrated in the perineum, trunk, and head and neck areas.

(ref: LIFTFL, BMJ)

Question 3

Risk factors

Answer 3

Young healthy people can get it (e.g. group A)
DM
ETOH abuse
PVD
renal failure
odontogenic infection
malignancy
chicken pox
local penetrating trauma or animal bite
recent surgery (e.g. abdominal or peritoneal surgery)
 (ref: LIFTFL)

Question 4

History + Examination

Answer 4

1. History
spreading erythema
sepsis (fever, chills, myalgias)
severe constant pain that is out of proportion to clinical findings
cutaneous anaesthesia
evidence of developing organ failures
underlying risk factors (See above)
commonly an extremity -> but can affect anywhere (e.g. perineum = Fournier’s gangrene)
Examination

2. Examination: Local:
erythematous, tender, swollen
skin becomes smooth, shiny and tensely swollen -> darkens, patchy, blisters and bullae -> gangrene
a wooden-hard feel of the subcutaneous tissue
oedema beyond the margin of erythema
crepitus (gas gangrene)
Systemic
  fever, tachycardia
  haemodynamic instability
Rapid spread on re-examination

Question 5

Management

Answer 5

aggressive rescustiation
surgical debridement
abx