The local Shwartzman reaction in the rabbit. Immunopathologic findings in the skin.

Four albino rabbits received two intradermal injections of endotoxin followed in 24 hours by an intravenous injection of endotoxin. All animals developed the local Shwartzman reaction, characterized by hemorrhagic necrosis over each intradermal injection site. Light microscopy of the Shwartzman lesion showed intense inflammation and vascular thrombosis. Frozen sections of the skin lesion revealed marked vascular deposition of fibrin with lesser amounts of IgG, IgM, C3, and albumin. Light microscopy was normal and immunofluorescence was negative in skin obtained prior to the initial injection of endotoxin and skin adjacent to the Shwartzman lesion. These findings suggest nonspecific trapping of serum proteins within vascular thrombi and indicate that immune mechanisms may not play a role in the pathogenesis of the local Shwartzman reaction.