Kounis Syndrome: A Report of Two Cases and a Review of the Literature.

Kounis syndrome (KS) is a rare condition in which allergic reactions activate mast cells and platelets, causing acute coronary syndromes (ACS), such as myocardial infarction, coronary vasospasms, or stent thrombosis. It can be triggered by drugs, food, vaccines, or insect bites. We report two cases involving elderly male patients. The first case describes a 71-year-old male with an allergy to non-steroidal anti-inflammatory drugs (NSAIDs), who accidentally ingested diclofenac and developed an allergic reaction with chest pain. In the emergency room, he was diagnosed with ST-elevation acute myocardial infarction (STEMI) and stent thrombosis in the right coronary artery, confirming a type III KS diagnosis. The second case involves a 73-year-old male with a history of prostate cancer and cerebral aneurysm, who had an allergic reaction after consuming dairy products, which was treated with cetirizine. Eight months later, he experienced a more severe reaction after eating fish, presenting with dizziness and chest pain. Elevated troponin levels and electrocardiographic changes indicated NSTEMI. Thereafter, it transitioned into a STEMI with atrial fibrillation with rapid ventricular response and was treated with thrombolytics and amiodarone. Finally, a medicated stent was implanted in the main vessel after a coronary arteriography.  These cases highlight the importance of considering allergic etiologies in the differential diagnosis of acute coronary syndromes to ensure accurate identification and tailored treatment.