[Reactions to iodinated contrast media].

ICPs are used for many radiological examinations but are responsible for 4.6 to 8.5% of secondary reactions, which may perhaps be of the toxic or anaphylactoid types. Asthma, taking of beta-blockers, and previous reactions to an ICP injection are risk factors for an anaphylactoid reaction. Several mechanisms are involved but it seems to be exceptional that there is an IgE-dependent reaction. There is no paraclinical examination for diagnosis or prediction of reactions. There are hyperosmolar ICPs and others, more recent, which are non-ionic, of reduced osmolality. Non-ionic ICPs induce only a quarter of the secondary reactions of all types together and the reactions are often less severe. When a new injection, they reduce the risk of recurrence in patients who have already had reactions. The best subject protection lies in a premedication with corticosteroids and use of a non-ionic ICP. The latter should also be prescribed if possible, in all where increase in osmolality is contraindicated.