Kounis syndrome uncovers severe coronary disease: an unusual case of acute coronary syndrome secondary to allergic coronary vasospasm

Acute coronary syndrome occurring during the course of a type I hypersensitivity reaction constitutes Kounis syndrome. We report a case of a 64-year-old man who presented with a non-ST elevation myocardial infarction and peripheral blood eosinophilia. He had rhinitis and constitutional symptoms for several days prior to presentation. Blood investigations revealed moderate eosinophilia and elevated IgE levels. A cardiac MRI showed generalised oedema with a subtle wall motion abnormality in basal inferior/inferolateral wall, and subendocardial high signal on late gadolinium enhancement suggesting a localised myocardial infarction. A coronary angiogram then revealed triple vessel disease. A diagnosis of Kounis syndrome was made. Within days of starting appropriate treatment, the patient's eosinophil count returned to normal with improvement of clinical picture.