Delayed adverse reactions to iodinated contrast media and their risk factors.

PURPOSE

The present prospective survey was performed to obtain information on delayed adverse reactions (DARs) to five types of low-osmolar iodinated contrast media, including their frequency, common manifestations, and the patient's history of allergy.

METHODS

We investigated data from 15,890 consecutive patients who underwent contrast-enhanced computed tomography (CT) during a 15-month period. All patients were given a questionnaire asking about the occurrence of DARs, their symptoms and duration, and asked to consult a dermatologist if they had a skin reaction.

RESULTS

Of 11,121 patients who returned the questionnaire (response rate, 70.0%), DARs were observed in 1,058 patients (9.5%). DARs tended to occur with higher incidence in patients with no previous history of examinations using contrast media, with past adverse reactions caused by contrast media, with a history of allergy, or with a serum creatinine level greater than 2.0 mg/dl. Among the 331 patients who reported skin reactions, 41 patients consulted a dermatologist. Skin reactions were observed significantly more frequently in patients for whom iotrolan was used, and 60% of these reactions were severe or moderate.

CONCLUSIONS

Four risk factors for DARs were identified in the present investigation.