Successful administration of iodinated contrast media in a patient with anaphylaxis to multiple contrast media

Successful administration of iodinated contrast media in a patient with anaphylaxis to multiple contrast mediaAlthough hypersensitivity reactions to iodinated contrast media (ICM) are uncommon, their clinical impacts are considerable because of their wide use and potential fatality. The best way to prevent ICM-induced hypersensitivity is to avoid re-exposure to the ICM. However, ICM use is inevitable in the evaluation of many diseases. A 64-year-old male with renal cell carcinoma presented with anaphylaxis after computed tomography (CT) using iohexol. Intradermal test results were positive to iohexol, iomeprol, and ioversol. The following 3 CT scans using the test-negative agents iopromide, iopamidol, and iobitridol still provoked hypersensitivity reactions despite premedication using intravenous antihistamine and corticosteroid. For the next step, iodixanol, a nonionic iso-osmolar dimer, was tested by intravenous graded challenges in addition to the intradermal skin test, which and was confirmed to be negative. The patient underwent CT scan using iodixanol after premedication with chlorpheniramine 4 mg and methylprednisolone 40 mg, and hypersensitivity reactions did not recur. We report a case of a patient showing hyper reactivity to multiple ICMs despite negative intradermal skin tests, who eventually underwent successful enhanced CT scans after choosing ICM by the graded challenge test.