The Allergic Heart That Falls Apart: Type 1 Kounis Syndrome Following Concomitant Diclofenac and Ondansetron Intake

Kounis syndrome is an underrecognized cause of acute coronary syndrome characterized by the coexistence of allergic reactions and myocardial ischemia. We report a case of Type 1 Kounis syndrome in a 51-year-old male who presented with acute chest discomfort, diaphoresis, and dyspnea following ingestion of diclofenac and ondansetron. Initial evaluation revealed transient anterior wall ST-segment elevation (V2-V5) with normal cardiac biomarkers and no regional wall motion abnormalities. The patient was initially managed for acute coronary syndrome; however, rapid resolution of symptoms and electrocardiographic changes, along with normal echocardiography and coronary angiography findings, suggested an alternative diagnosis. Clinical features, including GI symptoms without cutaneous manifestations, further supported an atypical allergic presentation. He was treated with intramuscular epinephrine, antihistamines, and corticosteroids, with prompt clinical improvement. A diagnosis of Type 1 Kounis syndrome secondary to drug-induced coronary vasospasm was established. This case underscores the importance of early recognition of Kounis syndrome in acute coronary presentations, particularly in the absence of biomarker elevation and obstructive coronary disease.