Necrotising fasciitis

Question 1

What is the pathophysiology of necrotising fasciitis?

Answer 1

Proliferation of pathogenic bacteria in tissue forming gas and necrosing fascia and thrombosing blood vessels 🡪 hypoxia 🡪 necrosis and pain

Question 2

What is type 1 nec fasc caused by?

Answer 2

• Polymicrobial (anaerobes and Enterobacteriaceae)

- Polymicrobial is common in DM pts

Question 3

What is type 2 nec fasc caused by?

Answer 3

Group A Strep (pyrogenic toxins A/B/C) or Staphylococcus aureus (enterotoxins and Panton-Valentine leukocidin PVL)

Question 4

What is type 3 nec fasc caused by?

Answer 4

Marine (Aeromonas, Vibrio)

Question 5

what is the presentation of necrotising fasciitis?

Answer 5

• Rapid progression, redness, bullae, pain out of proportion to physical exam
• +/- crepitations (from subcu gas)

Question 6

what are the complications of nec fasc?

Answer 6

toxic shock syndrome (TSS), septic shock

Question 7

what are the investigations of nec fasc?

Answer 7

• Imaging: visualise fluid/gas in subcu tissue

- Culture confirms aetiological pathogen

Question 8

what is the mx of nec fasc?

Answer 8

• IV abx

- Early and aggressive debridement of necrotic tissue