Anaerobic Infections, Skin & Soft Tissue

Key Features

• 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

• 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

• Surgical exploration

Treatment

• 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