Kounis syndrome: A manifestation of drug-eluting stent thrombosis associated with allergic reaction to contrast material

Stent components acting as potential antigens and promoting intracoronary mast cell activation can lead to catastrophic intrastent thrombosis. Patients with drug-eluting stent (DES) implantation are prone to hypersensitivity reactions from five potential antigens namely, nickel strut, polymer coating, eluted drug, as well as, concomitant drugs clopidogrel and aspirin. These events may be more common than suspected because it is hard to document them, unless they become systemic, in which case they manifest themselves as the Kounis syndrome characterized by the concurrence of acute coronary events with hypersensitivity reactions. This report concerns of a patient with implanted DES who developed an acute myocardial infarction in the stent area following an allergic reaction to contrast material.