Interest of Challenge Tests for Diagnosis of Immediate Hypersensitivity Against Iodinated Contrast Agents

Iodinated contrast agents (ICA) are widely used in medical imaging. They provide however a risk of immediate hypersensitivity reactions (IHS). The risk of anaphylactic shock is estimated at 1/100 000 injections. Nevertheless, for safety reasons and to limit undesirable effects, the reintroduction tests are not conducted along similar lines to throughout scan or arteriography. Moreover, reintroduction protocols are actually not standardized, in terms of injected volume and doses progression. It should be evaluated the relevance of the reintroduction tests with injection of a low volume and ensure the absence of reaction during the ICA injections Under real conditions.

The investigators are assuming that the realization of a provocation test by intravenous reintroduction with a reduced dose of ICA improves the predictive value of IHS in comparison with only cutaneous tests.