Local Skin Reactivity to "Filtrates" of Pneumococcus

Abstract

Shwartzman,1 working with filtrates of cultures of a number of bacteria, has elicited a reaction in rabbits, which he has designated phenomenon of local skin reactivity. This phenomenon is produced by injecting a small amount of toxic bacterial filtrate intradermally in the shaved or epilated skin of the abdomen of a rabbit. From twenty to twenty-four hours later, a much larger dose of the same bacterial filtrate is injected into the marginal vein of the ear of the rabbit. Within five hours, a hemorrhagic, black, necrotic area, usually sharply defined, appears at the site of the intradermal injection. Shwartzman demonstrated that in the case of the filtrate prepared from Bacillus typhosus and that prepared from Meningococcus this reaction could be prevented entirely or in part by neutralizing these filtrates with commercial antiserums before the intravenous injection.2 In a later article3 he demonstrated the practical results that have ensued from the use of the phenomenon of local skin reactivity, in addition to the purely scientific aspect of the reaction. During the past year, workers in the laboratory of the Nelson Morris Institute have been interested particularly in studying Meningococcus and Pneumococcus. It was thought that the phenomen of local skin reactivity might offer a rapid, accurate method of determining type specificity, information which would be of greater clinical value than that obtained by agglutination reactions.