Shwartzman reaction

vasculitis, local or systemic, caused by a two-stage reaction in which a first encounter with endotoxin produces intravascular fibrin thrombi whose clearance results in reticuloendothelial blockade which prevents the clearance of thrombi caused by a second encounter with endotoxin, (or a variety of polyanions, glycogen or antigen/antibody complexes) resulting in tissue necrosis and/or hemorrhage; in pregnancy gram-negative septicemia during delivery or abortion may serve as the first or provocative encounter.