Necrotising fasciitis

Question 1

Define

Answer 1

a life-threatening infection that spreads rapidly across fascial planes

Question 2

What are the risk factors?

Answer 2

o	Diabetes 
o	Alcoholism 
o	Peripheral vascular disease 
o	Leg ulcers 
o	Varicella zoster infections
o	Malignancy 
o	Immunosuppression 
o	Steroid use 
o	Puncture/surgical wounds

Question 3

What is the aetiology?

Answer 3

o Usually polymicrobial involving streptococci, staphylococci, bacterioides and coliforms
o Type I (polymicrobial) and type II (monomicrobial, streptococcus pyogenes)
o Fournier’s gangrene – of scrotum or male perineum

Question 4

What are the presenting symptoms?

Answer 4

o Pain/ anaesthesia
• Often seems SEVERE and out of proportion to the apparent physical signs
o Predisposing event (e.g. trauma, ulcer, surgery)
o Systemic infection symptoms: Fever, palpitations, hypotension, lightheadness, nausea and vomiting

Question 5

What are the signs?

Answer 5

o Area of erythema and oedema, grey discolouration
o Haemorrhagic blisters may be present
o Signs of systemic inflammatory response and sepsis (high/low temperature, tachypnoea, hypotension)

Question 6

What are the investigations?

Answer 6

• Bloods - FBC, U&Es, glucose, CRP and blood culture, lactate, gram stain, ABG
• Wound Swab, Pus/Fluid Aspirate - MC&S
• X-ray of affected area - may show gas produced in gas gangrene