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Index: WOUNDS 2011;23(9):E27–E33

  Necrotizing fasciitis (NF) is a life-threatening soft tissue infection caused by toxin-producing bacteria. It is a serious, alarming condition for the surgeons because of its propensity for extensive soft tissue destruction and high mortality rate. The infection can be associated with severe systemic toxicity and can rapidly progress to death unless recognized and treated promptly. Fortunately, this type of dermal gangrene is relatively rare in modern surgical practice. Presumably, antibiotics have helped to reduce the incidence of the disease. There is a five-fold increase in the incidence of the disease over the last few decades, which is largely unexplained, although increased longevity within the overall population and an increase in the number of immunosuppressed individuals may be two of the main causes.^1,2

  The disease was recognized by Hippocrates in the 5th century AD, who spoke of it as a complication of erysipelas.³ The disease was first identified in 1848. In the United States, it was first described in 1871 by a Civil War surgeon who described cases of hospital gangrene. Meleney then identified and described the disease in 1920, but the term NF was introduced by Wilson in 1952. Since then, other terms have been used to refer to NF, including necrotizing soft tissue infection, streptococcal gangrene, gas gangrene, bacterial synergistic gangrene, hospital gangrene, flesh-eating bacteria syndrome, Clostridial myonecrosis, Meleney’s synergistic gangrene, and Fournier’s gangrene, the latter being specific to the involvement of scrotum and perineum in males. Although many different names have been used to describe the various NF, they often have a common pathology.^1,4,5

  Despite the improvements in critical care, antibiotics, and surgical technology, mortality still ranges between 30% and 50%.^2,4 In complicated cases like renal failure and multi-organ system failure, the mortality rate goes up to 70%.^6,7 Among patients with NF, the mortality rate is higher in patients with streptococcal toxic shock syndrome. Because large prospective studies have not been performed, the factors that contribute to mortality cannot be stated with certainty. The following are the possible prognostic factors that contribute to mortality: the duration of time from onset of infection to definitive treatment; the type, extent, and adequacy of surgical debridement; and infection of the head and neck, thorax, and abdomen, which are more complex in terms of surgical debridement. Other risk factors that have been shown to correlate with increased mortality include advanced age (> 50 years), diabetes mellitus, co-existing systemic sepsis and development of organ failure, arteriosclerosis, chronic renal insufficiency, congestive cardiac failure, and malnutrition.^7,8

  Two clinical types exist based on the organisms cultured from the wounds. Type I, or polymicrobial NF, is a mixed infection caused by aerobic and anaerobic bacteria. It occurs most commonly after surgical procedures, particularly after abdominal or perianal operations, and in patients with diabetes mellitus, peripheral vascular disease, and immunodeficiency syndrome. It can follow trauma, lung infection, dental extraction, cardiac catheterization, and usually no preceding history can be elicited, but there might be some easily forgotten trauma, such as minor laceration or insect bite. This form initially may be mistaken for a simple wound cellulitis. However, severe pain and systemic toxicity which reflect widespread tissue necrosis of underlying, apparently viable, skin apart from the wound site differentiate it from wound cellulitis.