diagnosis

Last reviewed 01/2018

The diagnosis of necrotising fasciitis is overridingly clinical. There must be low threshold for diagnosis if the following features are present:

  • skin changes:
    • erythema
    • low-grade cellulitis
    • cyanotic discolouration or ecchymosis
    • epidermolysis or bullae
    • skin necrosis
    • anaesthesia of skin beyond the margin of surface colour change
    • crepitus
  • a hard, indurated feel to the subcutaneous tissue which is present beyond the visible limits of skin involvement
  • pain out of proportion to the visible surface changes
  • signs of systemic toxicity with altered mental status, fever, shock or acute renal failure
  • minimal improvement despite initial antibiotic therapy

A number of blood investigations may support the diagnosis. Imaging should not delay the patient progressing to theatre for rapid, adequate debridement.

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