Necrotizing fascitis

A rapidly progressive, extremely destructive bacterial infection of the deep layers of the skin and fascia, often associated with Streptococcus pyogenes or mixed bacteria. In popular media, it may be called "flesh-eating bacteria". Onset is subtle, beginning with fever and chills, but, after several days, reddening of the skin, with skin lesions including vescicle or bullae. There may be drainage.

It can develop at any puncture site, or where there is internal destruction as from fractures, frostbite, compartment syndrome, or surgery. Other infections, such as varicella, can make the patient vulnerable.

Three clinical forms are recognized; all are surgical emergencies

• Type I, or polymicrobial NF, usually occurs after trauma or surgery. It may present as simple cellulitis, but disproportionate pain and systemic symptoms should be warnings.
• Type II is the streptococcal, rapidly destructive form
• Type III is gas gangrene, from Clostridium perfringens or Clostridium septica, usually after trauma.