necrotising fasciitis

Question 1

what is the typical presentation of necrotising fasciitis?

Answer 1

Systemic signs, rapidly spreading, redness/discoloration, severe pain and blistering

Question 2

outline the aetiology of necrotising fasciitis?

Answer 2

T1 (more common) – polymicrobial infectionof subcutaneous tissue (anaerobe e.g. Bacteriodes or Peptostrep + facultative anaerobe e.g E.coli, enterobactoer, klebseiella)

T2 – monomicrobial infectionof subcut tissue (strep pyogenes (GAS),staph A, MRSA, Aeronmonas hydrophilia and vibrio vuknificus)=

Question 3

what are the risk factors for necrotising fasciitis?

Answer 3

• Cutaneous injury, surgeryor trauma
• DM
• PVD
• Immunocompromised
• Chronic renal/ hep insufficiency
• Chickenpox
• Herpes zoster
• IV drug use

Question 4

what are the signs and symptoms of necrotising fasciitis?

Answer 4

Anesthesiaor severe pain over site of cellulitis

Signs and symptoms of systemic infections: fever, palpitations, tachycardia, tachypnoea, hypotension and lightheadedness, N+V, delirium

Discoloration of skin

Question 5

what are the investigations for necrotising fasciitis?

Answer 5

FBC – high WBC (if v. low may be a sign of sepsis)

U&Es – hyponatremia, high urea and cr, high crp

high CK, lactate (systemic infection finding)

+ve blood and tissue cultures – definitive diagnosis

Xray/CT/MRI in all pts with necrotising fascitis if clinically app – may show abnormalities of soft tissue

Surgical inspection, exploration, and drainage of infected tissue