Novel Strategy for the Prevention of Recurrent Hypersensitivity Reactions to Radiocontrast Media Based on Skin Testing

Background Hypersensitivity reactions to iodinated contrast media (ICM) is a persistent clinical issue with increased use of computed tomography. With the evidence indicating underlying allergic mechanisms, there have been studies regarding the skin tests using ICM. Objective This study aimed to evaluate the intradermal skin test (IDT) as a tool for preventing recurrent hypersensitivity reactions to ICM in patients with prior reactions to a known culprit agent. Methods Sixty-nine patients who had experienced immediate hypersensitivity reactions to ICM were included in the study. All patients underwent IDT with 7 different ICMs, including the causative ICM. We analyzed clinical data from 38 patients who were reexposed to ICMs, grouped by the IDT results to their original culprit ICM. Results Thirty-eight patients showed positive IDT results to the culprit ICM (CULPRIT+), whereas 31 patients showed negative results (CULPRIT−). Sixteen patients from the CULPRIT+ group and 22 from the CULPRIT− group were subsequently exposed to an ICM. In the CULPRIT+ group, 4 of the 5 patients who were subsequently exposed to an IDT-positive ICM reexperienced hypersensitivity reactions. When patients were exposed to IDT-negative ICM as an alternative, hypersensitivity reactions were not observed. In the CULPRIT− group, IDT-positive ICMs did not provoke hypersensitivity reactions whereas 2 patients using IDT-negative ICMs experienced hypersensitivity reactions. Conclusions When the IDT results are positive for the culprit ICM, additional IDTs with other ICMs are needed to select a safe alternative. If the IDT results are negative against the culprit ICM, further IDTs might not play a role in selecting a safe alternative.