Skin tests for the exploration of hypersensitivity reactions associated with iodinated contrast media.

BACKGROUND Iodinated contrast media (ICM) are responsible for multiple side effects, especially hypersensitivity reactions. These reactions can either be authentic allergies, or non-allergic hypersensitivity reactions. Skin tests (prick and intradermal tests) are simple to perform and can be of great help, especially if the ICM need to be re-used. The aim of the study was to assess the characteristics of the patients in whom skin tests were performed, and the results of these tests. METHODS This is a retrospective study from June 2014 to June 2019. All included patients had at least one episode of hypersensitivity reaction to ICM and underwent skin tests. RESULTS We included 35 patients aged 18 to 85 years. The iopromide was the most implicated ICM. The reactions were mainly cutaneous (n=30) and immediate (n=27). The skin tests were negative, except for two patients. The reuse of ICM occured in 11 patients: 9 with an ICM other than the one suspected and two patients with the same ICM. Among these patients, 5 did not have any premedication. Two of them had a second hypersensitivity reaction, the first with another ICM and the second with the same ICM. CONCLUSION One of the main pillars of allergic exploration is ICM skin testing, not only to prevent recurrence, but also to allow patients to benefit from ICM reuse, which are sometimes essential.