Adverse reactions to iodinated contrast media in patients with a history of allergies

Objective

To investigate the prevalence, patterns and influence factors for iodinated contrast media (ICM)-related adverse reaction (AR) in patients with a history of allergies.

Methods

Patients with a history of allergies who underwent contrast-enhanced CT between January 2014 and December 2020 were enrolled. ICM-related AR and patient information were retrospectively analyzed. χ² and Student t test were used to compare between different groups, and logistic regression analyses were adopted to investigate influence factors for AR.

Results

325243 patients performed contrast-enhanced CT examinations. 713 cases with ICM allergy history and 27045 cases with non-ICM allergies history were included. The overall AR incidence was 0.66% (184/27758) and severe AR occurred in 0.05% (14 of 27758). 90.22% (166/184) of AR occurred within 20 minutes after injection. 2 severe AR occurred more than 30 minutes in patients with non-ICM allergies history. Compared with other ICMs, iodixanol was associated with higher incidence of AR in patients with ICM allergy history (10.71%; 12 of 112) and non-ICM allergies history (1.1%; 46 of 4172). Iohexol was associated with lower incidence of AR in patients with non-ICM allergies history (0.24%; 17 of 7134). Age ≥70 years (OR, 0.2; P<0.001) and hypertension (OR, 0.6; P=0.025) were protective factors for ICM-related AR in patients with non-ICM allergies history.

Conclusions

In patients with a history of allergies, most AR occurred within 20 minutes after injection. The AR incidence was associated with ICM generics. Age ≥70 years and hypertension were protective factors for ICM-related AR in patients with non-ICM allergies history.