Necrotising fasciitis

Question 1

NF: definition

Answer 1

life-threatening infection of the subcutaneous soft tissue, with spread along the fascial planes but NOT THE UNDERLYING MUSCLE

Question 2

Types

Answer 2

The most common are type 1 (polymicrobial infection with anaerobes) and type 2 (monomicrobial infection with group A streptococci e.g. strep pyogenes
Type III –> C perfringens

Question 3

NF: presentation

Answer 3

rapidly spreading cellulitis and are systemically very unwell. There is often a history of risk factors i.e. a cutaneous portal of entry for the bacteria (trauma/surgery).

blistering and erythematous. In early stages mild oedema may be the only sign. There will either be severe pain or anaesthesia over the site of cellulitis. In advanced cases, the skin may be grey, with overlying CREPITUS (type III). The patient is typically pyrexial, tachycardic, tachypnoeic, and hypotensive.

Question 4

NF: mx

Answer 4

haemodynamic support, urgent debridement surgery, and broad-spectrum antibiotics. Radiography or CT/MRI can confirm the diagnosis, but should not delay surgery.

Question 5

NF: risk factors

Answer 5

1. recent trauma, burns or soft tissue infections
2. diabetes mellitus
   the most common preexisting medical condition
   particularly if the patient is treated with SGLT-2 inhibitors
3. intravenous drug use
4. immunosuppression

Question 6

M/C location of NF

Answer 6

Perineum –> Fournier’s gangrene