The local Shwartzman reaction is a hemorrhagic and necrotizing inflammatory lesion elicited by endotoxin from gram-negative bacteria. Shwartzman1, 2 and Hanger3 demonstrated in rabbits that an intradermal injection of a sterile bacteria culture filtrate, containing endotoxin, followed by an intravenous injection of the same filtrate 20 to 24 hours later resulted in a local hemorrhagic and necrotic lesion developing at the site of the intradermal injection (Fig. 1). This reaction is now called the local Shwartzman reaction. It is a two-stage reaction requiring an initial preparatory intradermal injection of endotoxin and an intravenous injection of endotoxin 18 to 24 hours later. The time interval between injections is a crucial determinant for the reaction to occur, since if the intravenous injection of endotoxin is made much earlier or later, a hemorrhagic lesion at the site of the intradermal injection does not occur. It is interesting that the local Shwartzman reaction could be elicited in only 167 of 212 rabbits tested in the early experiments of Shwartzman. 2 Some rabbits who still showed erythema at the sites of intradermal injection at the time of intravenous challenge only developed a more pronounced erythema 4 to 5 hours after the intravenous challenge, but no hemorrhage or necrosis. Why some rabbits are resistant to developing a localized Shwartzman reaction is still not known.

A generalized Shwartzman reaction can be elicited by two intravenous injections of endotoxin spaced 18 to 24 hours apart. The generalized Shwartzman reaction first described by Sanarelli4 and Apitz5, 6 is a model for disseminated intravascular coagulation (DIC). Rabbits receiving a second intravenous injection of endotoxin become obviously ill within 4 to 6 hours after the