D1.244 - Retrospective Analysis of Adverse Reactions to Iodinated Contrast Media: Experience in 165 Patients

Analysis of clinical and demographic characteristics, along with the results of skin tests conducted on 165 patients between 2018 and 2024 at the Hospital Clínico Universitario de Valencia.

This is a retrospective descriptive study conducted over an 8-year period. A total of 165 patients (58 men and 107 women) who experienced adverse reactions following intravenous iodinated contrast administration were included.

Clinical and demographic data, including age, gender, and type of reaction, were collected from medical records. Additionally, the results of skin tests and imaging studies using iodinated contrast were analyzed to evaluate reactions identified during the allergological study.

A total of 9.09% (15 patients) had positive skin tests, with the majority (80%, or 12 patients) showing positive results on late readings. In 72% of the cases, the specific contrast agent involved was unknown. Among identified agents, Iohexol was most frequently associated with adverse reactions (16.36%), followed by Iodixanol (7.2%), Iomeprol (2.4%), and Iopromide (1.8%).Of the 150 patients with negative skin tests, 57 subsequently underwent imaging studies using iodinated contrast agents. All tolerated the procedures well, with only two patients reporting minor reactions described as "discomfort," dizziness, and hypertension.

While the literature indicates that Iodixanol is the non-ionic contrast agent most commonly associated with adverse reactions, Iohexol was the most frequently implicated agent in our hospital—likely reflecting its prevalent use locally.

It is notable that the majority of positive skin tests were detected on late readings (48 hours). Furthermore, patients with negative skin tests who were later exposed to intravenous iodinated contrast agents tolerated the procedures well, although it remains unclear if the same agent triggered the initial reaction.

Performing allergological studies with multiple iodinated contrast agents is essential, even in cases where the triggering agent is unidentified. This approach allows for the identification of safe alternatives and improved patient outcomes.