The derogation of leprosy in medieval culture was disproportionate to its medical threat, presumably influenced by the spectacle of a disintegrative process akin to putrefaction. In the medieval imaginary, leprous blood was linked to menstrual blood, supposedly discharged by both impure women and Jewish men, and believed to be a carrier of the disease. The perceived threat of leprous blood to Christian bodily integrity was played out in atropaic social rituals and in widespread defamations against lepers, women, and Jews as devourers or cannibals. This study claims that such practices worked to displace fundamental anxieties generated by the “sacramental cannibalism” of the eucharistic feast, in which the body and blood of Christ were fused with those of communicants through the process of ingestion. The medieval counternarrative mythologizing lepers, women, and Jews as would-be devourers served to insulate the sacramental status of the Eucharist, to distinguish pure from impure blood, and to displace the archaic fear of physical obliteration. However, of the three demonized groups it was the leper alone who was subject to a kind of double jeopardy: as a visible emblem of the instability of bodily boundaries, the leper served as both agent and illustration of the fearsomeness of physical dissolution.