Peripheral blood eosinophilia associated with gastrointestinal administration of iodinated contrast media

This study was designed to assess whether gastrointestinal administration of iodinated contrast media results in peripheral blood eosinophilia.

We studied 110 patients in a retrospective review. Diatrizoate meglumine and diatrizoate sodium for abdominal CT were administered to 98 of these patients; 22 of the 98 had also been given the same contrast medium administered by enema. The remaining 12 patients were given diatrizoate sodium for gastrointestinal fluoroscopy. A control group of 65 patients underwent single-contrast barium upper gastrointestinal or enema examinations. WBC and eosinophil counts were determined approximately 24 hr before the examination and every 24 hr thereafter, through the ninth day.

Eosinophilia was detected in 17 (15.5%) of 110 patients after gastrointestinal administration of iodinated contrast media. The prevalence of eosinophilia after administration of iodinated contrast media was statistically significantly different compared with that in the control group, in which none of the 65 patients had eosinophilia (p < 0.001). Eosinophilia was detected 48 hr after application of iodinated contrast agents and lasted through the sixth day, with a peak on the fifth day. The prevalence of eosinophilia was independent of route of application, dose, or type of iodinated contrast medium. Eosinophilia in all cases was clinically asymptomatic.

Eosinophilia that is caused by gastrointestinal administration of iodinated contrast media is a transient, clinically silent phenomenon. It may lead to unnecessary workup for known conditions associated with eosinophilia.