Cross-reaction between skin and skin streptococcus pyogenes antigens

Human skin contains precipitinogens and complement dependent antigen. Almost all Streptococcus pyogenes strains isolated from skin lesions [97%] possess cross complement dependent antigen which is reactive with the skin antiserum. A smaller number of the nasal strains and to a lesser extent the throat strains of the some patients [75% and 37.5% respectively] possess a similar antigen. Streptococcus group A strains isolated from nose [25%] and from tonsils [6%] of asymptomatic children contained the same complement dependent antigen Group C streptococci staphylococcus aureus and strains of gram negative bacilli all lacked this antigen. The antigen is a trypsin sensitive protein