Penicillin allergy in cancer patients manifesting as Kounis syndrome.

Two cases of allergic angina and allergic myocardial infarction (Kounis syndrome) following penicillin administration are described. The patients suffered from lung and mandible neoplasms and had previously received several courses of antineoplastic therapy without any sequelae. One patient had normal coronary arteries (type I variant of the syndrome) and the other had coronary artery disease with previous myocardial infarction (type II variant of the syndrome). The allergic reaction following penicillin administration seemed to have triggered the development of an acute coronary artery spasm in the first patient and an acute myocardial infarction in the second. This report shows that susceptible individuals expressing a magnified mast cell degranulation effect may be more vulnerable to coronary artery spasm and plaque erosion or rupture.