[Epidemiology and etiopathogeny of necrotizing fasciitis and streptococcal shock syndrome]

A significant increase in the frequency of necrotizing fasciitis caused by streptococci of group A has recently been noted. The disease usually appears in individuals without obvious risk factors. The initial lesion is often quite ordinary, and the evolution towards a toxic shock very swift. This evolution can be summarized as follows: 1) localized infection; 2) bacteraemia with circulating toxins and soft tissue necrosis; 3) production of cytokines by the immune cells of the host, leading to a rapidly irreversible toxic shock Serotypes 1, 3, 12 and 28 of group A streptococcus are usually involved. The virulence of some serotypes might be explained by the acquisition of a toxic gene. The sensitivity of the host is linked to the genetic expression of the V. beta. elements on the surface of lymphocytes. Antibiotics cannot save the patient when necrotizing fasciitis is installed. Surgery must be massive and performed early.