This case report discusses a rare occurrence of type II Kounis syndrome, characterised by an acute myocardial infarction triggered by an allergic reaction. The patient, a young adult male, experienced urticaria soon after eating oysters, which quickly escalated to severe chest discomfort. Despite lacking typical cardiac risk factors, the electrocardiogram showed indications of ST-elevation myocardial infarction. This condition was further complicated by ventricular fibrillation, necessitating urgent life-saving measures. This case demonstrates the intricate and often overlooked relationship between hypersensitivity reactions and cardiovascular events. It highlights the necessity for increased vigilance and rapid diagnostic and treatment approaches in handling Kounis Syndrome, especially in emergency situations. The case underscores the importance of considering allergic causes in acute cardiac scenarios, particularly in patients who do not have standard risk factors for coronary artery disease.

Allergic reactions related to drug use is a common entity presenting often from minor urticaria to life-threatening anaphylactoid reactions. A common but easily overlooked diagnosis, Kounis syndrome, is an established hypersensitivity coronary disorder induced by drugs, foods, environmental factors, and coronary stents that can present in the same way as non-allergy-induced acute coronary syndrome. Here within, we present a unique case of dual presentation of Kounis syndrome and prolonged QTc in a young patient after a single dose of Domperidone and Lansoprazole.

Kounis Syndrome is characterised by the concurrence of acute coronary syndrome with mast cell activation induced by inflammatory mediators released during an allergic reaction. Although several factors and diseases were reported to be associated with Kounis Syndrome, branched-chain amino acid supplements have not been previously reported as a cause of Kounis Syndrome. We present a 17-year-old boy admitted to our hospital with thoracic pain after the ingestion of a branched-chain amino acid supplement.

Coronary vasospasm can result from silent myocardial ischaemia to sudden death. There are many precipitant factors including different pharmacological agents. Kounis syndrome is defined by acute coronary syndromes associated with anaphylactic or anaphylactoid reactions. We report, to the best of our knowledge, the first paediatric case of Kounis syndrome due to intravenous atropine.