Suspected Type II Kounis Syndrome with Coronary Dissection Extending from the Distal Left Main into the Proximal Left Anterior Descending Artery After Wasp Sting Anaphylaxis: A Case Report

Kounis syndrome is an acute coronary syndrome occurring in temporal association with an allergic or anaphylactic reaction. Recognition may be particularly challenging in patients with established coronary artery disease, in whom hypersensitivity-mediated mechanisms may coexist with conventional causes of acute myocardial infarction. We report a 62-year-old man with known coronary artery disease and previous percutaneous coronary interventions who developed loss of consciousness, generalized urticaria, facial swelling, dyspnea, and hemodynamic instability shortly after two wasp stings. He received intramuscular adrenaline and supportive treatment for anaphylaxis. Severe chest pain subsequently developed, with ST-segment elevation and a dynamic increase in cardiac troponin. Emergency coronary angiography demonstrated a critical lesion extending from the distal left main coronary artery into the proximal left anterior descending artery. Intravascular ultrasound performed before stent implantation demonstrated an intimal flap and dissection plane. Intravascular ultrasound-guided percutaneous coronary intervention with drug-eluting stent implantation achieved a satisfactory acute result. Subsequent allergological evaluation demonstrated Hymenoptera venom sensitization; baseline serum tryptase measured approximately five weeks after the event was within the reference range. The close temporal relationship between anaphylaxis and myocardial infarction supports suspected type II Kounis syndrome, while coronary dissection was identified as the culprit lesion morphology; its causal relationship to the hypersensitivity reaction remains uncertain.