some for decreased number of debridements and decreased mortality (16,57). Results are
contradictory, with no real epidemiologically based studies performed (for treatment refer to
Table 3).
Fournier Gangrene
It originates as a necrotic black area on the scrotum. It is a fulminant, rapidly progressive
subcutaneous infection of the scrotum and penis, which spreads along fascial planes and may
extend to the abdominal wall. More than 60% of the patients have diabetes mellitus. Fournier
gangrene occurs commonly without a predisposing event or after uncomplicated hemor-
rhoidectomy. Less commonly this can occur after urological manipulation or as a late
complication of deep anorectal suppuration. Fournier gangrene is characterized by necrosis of
the skin and soft tissues of the scrotum and/or perineum that is associated with a fulminant,
painful, and severely toxic infection (58,59). The infection is usually polymicrobial. Successful
treatment is again based on early recognization and vigorous surgical debridement. Empiric
antibiotic treatment is appropriate until culture results are available. Infection is often
polymicrobial. The therapeutic benefit of hyperbaric oxygen treatment remains controversial
in this as well as other forms of NF.
Clostridial Myonecrosis (Gas Gangrene)
Clostridium perfringenstype A is the most common organism. Although initial growth of the
organism occurs within the devitalized anaerobic milieu, acute invasion and destruction of
healthy, living tissue rapidly ensues. Historically, clostridial myonecrosis was a disease
associated with battle injuries, but 60% of cases now occur after trauma. It is a destructive
infectious process of muscle associated with infections of the skin and soft tissue. It is often
associated with local crepitus and systemic signs of toxemia, which are formed by anaerobic,
gas-forming bacilli of theClostridiumsp. The infection most often occurs after abdominal
operations on the gastrointestinal tract; however, penetrating trauma, and frostbite, can expose
muscle, fascia, and subcutaneous tissue to these organisms. Common to all these conditions is
an environment containing tissue necrosis, low-oxygen tension, and sufficient nutrients (amino
acids and calcium) to allow germination of clostridial spores. The systemic manifestations of
gas gangrene are related to the elaboration of potent extracellular protein toxins, especially the
a-toxin, a phospholipase C (PLC), and, y-toxin, a thiol-activated cytolysin (17,18,60,61).
Clostridia are gram-positive, spore-forming, obligate anaerobes that are widely found in soil
contaminated with animal excreta. They may be isolated from the human gastrointestinal tract
and from the skin in the perineal area.C. perfringensis the most common isolate (present in
Figure 6 Postoperative view in a diabetic patient with necrotizing fasciitis of right leg due to group G
Streptococcus. Patient underwent debridement and fasciotomy.
Severe Skin and Soft Tissue Infections in Critical Care 305