IMID Medical Journal

   There is a number of reports of adverse reactions to Radiocontrast Agents (RAs), even though the possibility of using iodinated compounds with low osmolality has reduced the rate of incidence, if compared to the period in which iodinated RAs with high osmolality were mainly used. Adverse reactions to RAs, a potential expression of an (“allergic” or “non-allergic”) hypersensitivity or a toxic event, can be divided into “immediate” or “late” reactions, and are connected to multiple “risk factors”, even though those factors are identifiable in advance. Vasoactive mediators, like histamine, play, in any case, an important role in the pathogenetic mechanisms of hypersensitivity reactions. Diagnostics of adverse reactions to RAs use laboratory methods and, for late reactions, patch tests. As far as prevention is concerned, even though the important prophylactic role of pharmacological premedication is recognised, a prioritary attention is given to the anamnesis and clinical evaluation of the patient that will be investigated with RA.