Diagnosis and thereapy of necrotizing soft tissue infections of the perineum.

Nine patients with necrotizing soft tissue infection of the perineum and adjacent areas developed following perirectal absecess, retroperitoneal infection, local trauma or apparently spontaneously. Skin changes and crepitus were often present but severe local pain was the only indication of infection in three patients. Repeated surgery or in one case, a necropsy, were required to uncover the extensive, dissecting, purulent and necrotizing subcutaneous process. Myonecrosis had occurred in three cases. Operation was often delayed for several days because of the difficulty in recognizing the presence of infection or because the urgency for treating an already apparent infection was not appreciated. The mortality was high (5/9 cases). The bacterial isolates were predominantly of a mixed aerobic-anaerobic nature. Needle aspiration of suspicious areas, even where classic signs of inflammation are lacking and Gram staining of exudate are valuable procedures for diagnosis and institution of appropriate presumptive antibiotic treatment. Thorough surgical exploration and debridement must be performed promptly to maximize chances for survival.