Hypersensitivity Reactions to Contrast Media Used in Computed Tomography in Korea

Background: Contrast media have been widely used for the diagnosis of numerous diseases. Although they are generally safe, the reported number of hypersensitivity reactions to contrast media has increased annually. Objective: We aimed to investigate the incidence of hypersensitivity reactions due to intravenous nonionic contrast media. Also, we investigated whether the risk of contrast media-associated hypersensitivity was increased by specific types of contrast agents. Methods: We performed a retrospective review of patients who had hypersensitivity reactions after enhanced computed tomography scans at Bucheon St. Mary's Hospital, Bucheon, Korea from January 2016 to December 2019. We classified the hypersensitivity reactions into immediate (<1 hour) or delayed (≥1 hour) reactions. All demographic data and information regarding the hypersensitivity reactions were obtained from the electronic medical records. Results: The overall incidence of hypersensitivity reactions to contrast media was 0.49% (262 cases resulting from 53,733 exposures). The incidence increased annually from 0.19% in 2016 to 0.86% in 2019. Among the 262 cases, 199 cases (76.0%) were immediate-type while the delayed-type accounted for 63 cases (24.0%). The immediate hypersensitivity reaction incidence was not significantly different among contrast agents. However, the incidence of the delayed-type was significantly different (ranging from 0.02% for iomeprol to 0.25% for iodixanol, p<0.05). Conclusion: This study found that the hypersensitivity reaction incidence has increased annually. Immediate hypersensitivity reactions occurred at a higher rate than delayed hypersensitivity reactions. The incidence of delayed hypersensitivity reactions was significantly greater in patients who received iodixanol than in those who received the other types.