Necrotizing soft tissue infections: a primary care review.

Patients with necrotizing soft tissue infections often present initially to family physicians. These infections must be detected and treated rapidly to prevent loss of limb or a fatal outcome. Unfortunately, necrotizing soft tissue infections have no pathognomonic signs. Patients may present with some evidence of cellulitis, vesicles, bullae, edema, crepitus, erythema, and fever. They also may complain of pain that seems out of proportion to the physical findings; as the infection progresses, their pain may decrease. Magnetic resonance imaging and laboratory findings such as acidosis, anemia, electrolyte abnormalities, coagulopathy, and an elevated white blood cell count may provide clues to the diagnosis. No single organism or combination of organisms is consistently responsible for necrotizing soft tissue infections. Most infections are polymicrobial, with both anaerobic and aerobic bacteria frequently present. Fungal infections also have been reported. Generally, bacterial and toxin-related effects converge to cause skin necrosis, shock, and multisystem organ failure. Aggressive debridement of infected tissues is critical to management. Antimicrobial therapy is important but remains secondary to the removal of diseased and necrotic tissues.