Virulence determinant implicated in pathogenesis of scarlet fever is

Streptococcal Pyrogenic exotoxin ( erythrogenic, Dick, scarlatinal toxin): the toxin was named erythrogenic because it's intradermal injection into susceptible individuals produced an erythematous reaction. This test was used to identify children susceptible to scarlet fever, a type of acute pharyngitis with extensive erythematous rash, caused by Streptococcus pyogenes strains producing this toxin. The primary effect of the toxin is an induction of fever and so it was renamed streptococcal pyrogenic exotoxin. 3 types of SPE have been identified: A, B and C. Types A and C are coded for by bacteriophage genes while type B gene is chromosomal. SPE are superantigens, T cell mitogens that induce a massive release of inflammatory cytokines, causing fever, shock and tissue damage. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 213