Etiology

• Clostridium perfringens (> 80% of cases): a gram-positive, obligate anaerobic, spore-forming bacterium

• Less common: C. septicum, C. histolyticum

wounds with compromised blood supply create an optimal anaerobic environment for the proliferation of C. perfringens → necrosis that progresses within 24–36 hours

• Septic surgical wounds or procedures (e.g., bowel and biliary tract surgery, septic abortion)

• Deep, penetrating wounds (e.g., knife, gunshot)

• Open fractures

Ubiquitous C. perfringens spores contaminate a wound → bacterial reproduction under anaerobic conditions → ↑ secretion of exotoxins, especially C. perfringens alpha-toxin (a phospholipase lecithinase) → degradation of phospholipids → tissue destruction (myonecrosis), inhibition of leukocyte function, and gas production → gas separation into healthy tissue → further colonization and more local tissue destruction → further exacerbation of anaerobic conditions by the development of edema

• hours to days