Incidence of Elevated Cardiac Biomarkers in Patients Presenting to the Emergency Department With Allergic Symptoms: Implications for the Diagnosis of Kounis Syndrome

Noninfectious, allergic reactions affect many individuals and can range from mild to life-threatening. Kounis syndrome, an acute coronary syndrome triggered by allergic reactions, represents an association between allergies and myocardial ischemia. However, the significance of elevated cardiac biomarkers, particularly high-sensitivity cardiac troponin (hs-cTn), in patients presenting to the emergency department (ED) with allergic symptoms remains unclear. This study included consecutive patients who presented to the ED with symptoms of allergic reaction. All patients underwent serial electrocardiography and hs-cTnI testing. Patients with elevated hs-cTnI levels were further evaluated by dobutamine stress echocardiography. When acute coronary syndrome was suspected in an allergic context, coronary angiography was performed. Among the 200 patients studied, 52.5% were male, 5% had diabetes mellitus, and 24% had arterial hypertension. Urticaria was the most common manifestation, occurring in 73.5% of patients. Elevated hs-cTnI levels were detected in 12% of the patients, with 6% diagnosed with Kounis syndrome and the remaining 6% had myocardial injury without ischemia. Myocardial injury was more prevalent among patients with diabetes mellitus, arterial hypertension, dyslipidemia, and smoking history. Among the patients with Kounis syndrome, 8 had coronary disease, while only one with isolated myocardial injury had coronary artery disease. In conclusion, myocardial injury occurred in 12% of patients with allergic ED symptoms, with Kounis syndrome accounting for half of these cases. Elevated cardiac biomarkers during allergic reactions should prompt consideration of Kounis syndrome. Early recognition of this association is essential, particularly in patients with cardiovascular risk factors.