Kounis syndrome associated with hypersensitivity to hymenoptera stings

Hymenoptera stings can induce acute coronary syndromes by different pathogenetic mechanisms including direct action of the venom constituents on the coronary endothelium or allergic reaction with mediators acting on the coronary vasculature. Two patients were stung by wasps and honeybees and developed Kounis syndrome as a consequence of allergic reaction. Kounis syndrome is the concurrence of acute coronary syndromes with mast cell activation induced by allergic or hypersensitivity and anaphylactic of anaphylactoid reactions. It is caused via inflammatory mediators released through mast cell activation. The patients had pre-existing coronary artery disease (type II variant of Kounis syndrome) and the allergic reaction induced by hymenoptera stings seems to have triggered inflammatory mediator release. The pathophysiology and clinical implications of this association are discussed.