Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 33-31: Anaerobic Infections + Key Features Download Section PDF Listen +++ ++ Several terms have been used to classify these infections Bacterial synergistic gangrene Synergistic necrotizing cellulitis Necrotizing fasciitis Nonclostridial crepitant cellulitis Usually occur After trauma or surgery With inadequate blood supply In association with diabetes mellitus Most common in areas contaminated by oral or fecal flora All are mixed infections caused by aerobic and anaerobic organisms Although there are some differences in microbiology among these infections, their differentiation on clinical grounds alone is difficult + Clinical Findings Download Section PDF Listen +++ ++ There may be progressive tissue necrosis, evidence of gas in the tissues (crepitance) and a putrid odor Pain out of proportion to the clinical findings Hemodynamic instability and systemic toxicity may be present + Diagnosis Download Section PDF Listen +++ ++ Surgical exploration + Treatment Download Section PDF Listen +++ ++ Broad-spectrum antibiotics active against both anaerobes and gram-positive and gram-negative aerobes (eg, vancomycin plus piperacillin-tazobactam) should be instituted empirically and modified by culture results (Tables 30–4 and 30–5) Require aggressive surgical débridement of necrotic tissue for cure