Acute ST Elevation Myocardial Infarction Due to Allergic Reaction, Kounis Syndrome

Kounis syndrome is defined by the occurrence of an acute coronary syndrome (ACS) in the setting of an allergic, hypersensitivity or anaphylactic condition. Degranulation of mast cells and platelet activation leading to the release of multiple inflammatory mediators are thought to make the arterial circulation susceptible to acute cardiac events. It is an often underdiagnosed entity in the emergency setting, due to lack of awareness among emergency providers. Identifying Kounis syndrome is critical, since managing ACS differs from that of a classical acute myocardial infarction. We present the case of a 72-year old male patient with a history of stable coronary disease who presented to the emergency department with a diffuse pruritic rash and chest pain. Electrocardiogram showed ST elevation myocardial infarction. Urgent coronary angiography revealed total occlusion of the mid left anterior descending coronary artery which was treated with a drug eluting stent with an excellent outcome. The pruritic rash responded to treatment with intravenous corticosteroids and antihistamines; No allergens were identified. The patient's symptoms resolved and he had an uneventful hospitalization. The diagnosis of Kounis syndrome can complicate the management of acute allergic reactions. Special precautions should be taken by emergency physicians with regards to the administration of beta blockers, morphine and vasodilators, which may be detrimental in this setting.