Eosinophilia caused by iodinated radiographic contrast media

Statistically significant eosinophilia was noted in the peripheral blood of a group of 108 patients 48 h after the administration of iodinated radiographic contrast medium (RCM). The duration of eosinophilia was approximately 6 days. Eosinophilia had no accompanying clinical symptoms except for two cases where urticaria appeared. The incidence of eosinophilia was irrespective of dosage or type of RCM. Possible mechanisms responsible for eosinophilia have been considered. Since eosinophilias of other aetiologies are common, it is of practical importance to distinguish these from RCM-induced eosinophilias.