“…The mechanism can only be conjectured. Injection of erythrogenic toxin from scarlatinal strains produces a radiating flare of pink lymphatic vessels (Okell 1932), and erythema, induration and cedema can be induced in rabbits by the intradermal injection of a solution obtained by mechanical disruption of Group A streptococci or by injection of cell wall extracts together with live streptococci (Schwab 1965). Hypersensitivity is not a factor in this reaction; hyaluronidase may result in the spread of the lesion once established.…”