• Clinical science

Gas gangrene


Gas gangrene (also known as clostridial myonecrosis) is a life-threatening necrotizing soft tissue infection commonly caused by the rapid proliferation and spread of Clostridium perfringens from a contaminated wound. The clinical picture includes excruciating muscle pain, edema with subsequent skin discoloration (red-purple to black) and gas production. Crepitus, as well as a feathering pattern of gas in soft tissue imaging, are generally present. Without treatment, gas gangrene is fatal in almost 100% of cases; surgical debridement in combination with antibiotic therapy reduces this figure by half.


  • Pathogen
    • Clostridium perfringens (over 80% of cases): a gram-positive, obligate anaerobic, spore-forming bacilli
      • Blood agar: double zone of hemolysis surrounds colony of bacteria
    • Less common: Cl. septicum, Cl. histolyticum
  • Path of infection
    • Ubiquitous clostridial spores contaminate the wound
    • Wounds with compromised blood supply create an anaerobic environment → optimal for the proliferation of C. perfringensnecrosis progresses within 24–36 hours. Such wounds include:


Ubiquitous C. perfringens spores contaminate a wound → bacteria reproduce under anaerobic wound conditions → these bacteria secrete exotoxins, especially alpha toxin, a phospholipase → degrades phospholipids → tissue destruction, inhibition of leukocyte function, and gas production → the gas separates healthy tissue, which facilitates further colonization and causes more local tissue destruction → anaerobic conditions are further exacerbated by the development of edema

Clinical features

  • Incubation period: hours to days
  • Local signs and symptoms
    • Spreading infection (see classic signs of inflammation)
    • Excruciating muscle pain
    • Massive edema with bronze → red-purple → black skin discoloration and overlying bullae
    • Sweet, foul-smelling, or nonodorous discharge produced by anaerobic metabolic products
    • Crepitus
  • Systemic toxicity
    • Can progress to systemic infection within a few hours
    • Early signs: fever, tachycardia, altered mental status
    • Late signs: shock; , hemolytic anemia, ARDS, kidney and liver failure, multi-organ failure [1][2]

Gas gangrene is a medical emergency that can rapidly progress to a severe clinical course with multi-organ failure!


  • Imaging: radiography, CT, or MRI typically show a characteristic feathering pattern of the soft tissue.
  • Laboratory tests
    • Gram staining: large, gram-positive rods
    • Blood cultures (although only 1% are positive)
    • PCR or ELISA for detection of toxin in wound material (not widely available)
  • Surgical exploration
    • Affected muscle does not bleed or contract, and may be pale or discolored red-purple to black
    • Histopathological findings of biopsy
      • Myonecrosis and destruction of surrounding degenerative tissue(muscle, skin fat, subcutaneous tissue)
      • Presence of organisms; without inflammatory infiltrate [1]

Differential diagnoses

  • Necrotizing fasciitis
  • Vibrio vulnificus infection
    • May occur after an open wound is exposed to seawater contaminated with V. vulnificus
    • Gram stain and culture to distinguish (V. vulnificus is gram-negative)
  • Group A Streptococcus infection
  • Rhabdomyolysis [1]
  • Pyomyositis

The differential diagnoses listed here are not exhaustive.


The most important steps of management are immediate surgical debridement and antibiotic therapy. Patients should receive supportive therapy and intensive care.