What causes necrotizing fasciitis?

Necrotizing fasciitis has been well described for years but has recently received much attention in the lay press as the “flesh-eating bacteria.” It is a bacterial infection that is rapidly progressive, often over hours, destroying muscle and subcutaneous tissues. Death or loss of a limb may occur, if it is not diagnosed and treated early in its course. It is most commonly associated with b-hemolytic streptococci but may also be due to other gram-positive or gram-negative organisms, or it may be polymicrobial.

Sarani B, Strong M, Pascual J, Schwab CW: Necrotizing fasciitis: current concepts and review of the literature, J Am Coll Surg 208:279–288, 2009.