Aspirin/regadenoson: Kounis syndrome type II and pruritus.

A 64-year-old man experienced Kounis syndrome type II and pruritus after receiving regadenoson for stress myocardial perfusion imaging and aspirin for coronary artery stenosis. The man initially presented with chest pain and ST segment elevation after regadenoson administration, which was resolved with nitroglycerin. Further investigation revealed calcified stenosis of the coronary artery and systemic mastocytosis. The man was diagnosed with Kounis syndrome type II caused by regadenoson and aspirin was discontinued, with the patient remaining on ticagrelor monotherapy. [Extracted from the article]