Anaphylactoid reactions to iodinated contrast media.

The mechanisms of immediate reactions to iodinated contrast media (ICM) are currently debated. Most of them and especially the minor and mild ones are being attributed to a direct, non-specific effect of the molecule (1), and a smaller number of severe cases, are suspected to be anaphylactic, IgE-depending events (2). The purpose of this study was to investigate reactions occurring immediatly after ICM injection by measuring histamine and tryptase, two specific markers of basophil and/or mast cell activation. Some patients agreed to be skin-tested in order to detect a sensitization to ICM.