Necrotising Fasciitis

Question 1

Define necrotising fasciitis.

Answer 1

Necrotising fasciitis is a life-threatening subcutaneous soft-tissue infection that may extend to the deep fascia, but not into the underlying muscle.

Question 2

Explain the aetiology/risk factors of necrotising fasciitis.

Answer 2

Inpatient contact with index case
Varicella zoster infection
Cutaneous injury, surgery, trauma
Non-traumatic skin lesions
Intravenous drug use

Question 3

Summarise the epidemiology of necrotising fasciitis.

Answer 3

Absolute data for the incidence and prevalence of necrotising fasciitis are lacking. There is no trend towards an increase or decrease in the prevalence or incidence of necrotising fasciitis, or evidence of global differences in epidemiology.

Question 4

Recognise the presenting symptoms of necrotising fasciitis. Recognise the signs of necrotising fasciitis on physical examination.

Answer 4

Anaesthesia or severe pain over site of cellulitis
Fever
Palpitations, tachycardia, tachypnoea, hypotension, and lightheadedness
Nausea and vomiting
Delirium
Crepitus
Vesicles or bullae
Grey discoloration of skin
Oedema or induration

Question 5

Identify appropriate investigations for necrotising fasciitis and interpret the results.

Answer 5

Full blood count and differential
Serum electrolytes
Serum urea and creatinine
CRP
CK
Serum lactate
Blood and tissue cultures
Gram stain
ABG
CT/MRI
Surgical exploration