Necrotising fascitis

Question 1

Definition of necrotising fasciitis

Answer 1

Rapidly progressive inflammatory infection of the fascia- progresses along fascial planes
Secondary necrosis of subcutaneous tissue and skin

Question 2

Epidemiology of necrotising fasciitis

Answer 2

Increased incidence
Around forty years
Rare in children
Diabetics, alcoholics, cirrhosis

Question 3

Risk factors for necrotising fasciitis

Answer 3

Diabetes
Cancer
Cirrhosis
Renal failure
NSAID use in varicella

Question 4

Symptoms of necrotising fasciitis

Answer 4

Early: hard to recognise
Rapid progression to intense pain
Fever
Myalgia

Question 5

Signs of necrotising fasciitis

Answer 5

Initial trivial lesion
then erythema
then purple
then gangrenous

Oedema
Vesicle- clear or bloody
Crepitus/gas gangrene

Question 6

Investigations of necrotising fasciitis

Answer 6

Clinical diagnosis
Treat without delaying for investigation

High WCC
High urea
ABG
Cultures- blood + tissue

Look for streptococcal pyrogenic exotoxin

MRI

Question 7

Aetiology of necrotising fasciitis

Answer 7

Infection of fascia by Group A streptoccoccus

Question 8

BONUS: causative organism of erysipelas?

Answer 8

Group A beta haemolytic streptococcus- strep pyogenes