Eosinophilia, a component of the allergic response, may occur after the use of iodinated radiographic contrast media for intravenous urography. A benign transient elevation in differential eosinophil count was seen in 21 of 101 patients following the injection of iodinated contrast agents for that purpose.
(JAMA 237:2629, 1977)
Vincent ME, Gerzof SG, Robbins AH. Benign Transient Eosinophilia Following Intravenous Urography. JAMA. 1977;237(24):2629. doi:10.1001/jama.1977.03270510051023