Severe skin and soft tissue infections and associated critical illness.

Skin and soft tissue infections (SSTIs) span a broad spectrum of clinical entities from limited cellulitis to rapidly progressive necrotizing fasciitis, which may be associated with septic shock or a toxic shock-like syndrome. These infections may be the primary instigators of critical illness requiring hospitalization and management in the intensive care unit. Alternatively, these infections may arise from metastatic spread of microorganisms from a distant focus. Regardless of the source, SSTIs may lead to critical illness. The complex interplay of environment, host, and pathogen are important to consider when evaluating SSTIs and planning therapy. This second of a two-part review focuses on severe SSTIs due to Clostridium spp, microorganisms associated with water sources, and polymicrobial/mixed infections. The key to a successful outcome is early identification of risk factors for specific pathogens and early initiation of empiric antimicrobial therapy. For some SSTIs, surgical intervention for diagnosis and/or therapy is also required.