Summary

Background:

Management of patients with reported iodinated contrast media (ICM) allergy is not supported by sufficient data. It is assumed that these patients are at risk for severe reactions, and that premedication provides protection.

Objective:

To examine current practice and prognosis in hospitalized patients with ICM allergy.

Methods:

In this retrospective study, we analyzed data of 17,356 patients who were hospitalized between 2018 and 2022 and referred for imaging. No-allergy and allergy groups were matched by age, sex, co-morbidities, and indications for imaging. Statistical analysis compared demographic, clinical, and imaging-related parameters.

Results:

Our study included records of 501 patients with ICM allergy and 16,855 with no allergy. Patients with allergy were older (70.92 ± 16.25 vs. 59.02 ± 23.74 years, P < 0.001), female preponderance (male proportion 42.5% vs. 54%, P < 0.001), and those with increased cardiovascular and metabolic co-morbidities. The rate of ICM injection was similar among patients with ICM allergy (34%) and no allergy (36%). Most patients with ICM allergy did not receive premedication. Allergic patients demonstrated increased mortality (25.9% vs. 16.5%, P < 0.001); however, this result was not associated with the diagnosis of allergy, anaphylactic reactions, or premedication.

Conclusions:

ICM allergy is mostly reported in patients with advanced age and multiple co-morbidities. Mortality was not increased when compared to matched non-allergic individuals. Among patients with reported allergy who were injected with ICM, anaphylaxis was not a cause of death, although fewer than half received premedication. Prospective trials are warranted to revise the clinical approach to ICM allergy.