For those patients in whom radiologic drainage is not successful, surgical exploration and evacuation are indicated. The standard approach to initial antibiotic therapy is the combination of ampicillin, gentamicin, and clindamycin. Adequate treatment can be achieved with available broad-spectrum single agents (including the broad-spectrum penicillin), second-and third-generation cephalosporins, levoﬂoxacin and metronidazole, and the sulbactam-clavulanic acid–containing preparations (101).
Necrotizing Fasciitis Necrotizing fasciitis is an uncommon infectious disorder, affecting roughly 1,000 patients per year (102). This disease process is characterized by a rapidly progressive bacterial infection that involves the subcutaneous tissues and fascia while characteristically sparing underlying muscle. Systemic toxicity is a frequent feature of this disease, as manifested by the presence of dehydration, septic shock, disseminated intravascular coagulation, and multiple organ system failure.
The pathogenesis of necrotizing fasciitis involves a polymicrobial infection of the dermis and subcutaneous tissue. Hemolytic streptococcus was initially believed to be the primary pathogen responsible for the infection in necrotizing fasciitis (103). Other organisms are often cultured in addition to streptococcus, including other gram-positive organisms, coliforms, and anaerobes (104). Bacterial enzymes such as hyaluronidase and lipase released in the subcutaneous space destroy the fascia and adipose tissue and induce a liquefactive necrosis. Noninﬂammatory intravascular coagulation or thrombosis subsequently occurs. Intravascular coagulation results in ischemia and necrosis of the subcutaneous tissues and skin. Subcutaneous spread of up to 1 inch per hour can be seen, often with little effect on the overlying skin (104). Late in the course of the infection, destruction of the superficial nerves produces anesthesia in the involved skin. The release of bacteria and bacterial toxins into the systemic circulation can cause septic shock, acid-base disturbances, and multiple organ impairment.