Getting under the skin: the immunopathogenesis of Streptococcus pyogenes deep tissue infections.

Streptococcus pyogenes can cause a variety of diseases in immunocompetent individuals, from pharyngotonsillitis to life-threatening invasive diseases, such as streptococcal toxic shock syndrome, and rapidly progressing deep-tissue infections, such as necrotizing fasciitis. Necrotizing fasciitis is often seen in combination with streptococcal toxic shock syndrome, which further increases morbidity and mortality. We review here the host-pathogen interactions in the tissue milieu and discuss the use of intravenous immunoglobulin as potential adjunctive therapy in these life-threatening infections.