title: Macular exanthema appearing 5 days after X-ray contrast medium administration.
abstract: We report a case of widespread, pruritic macular exanthema appearing 5 days after intravenous administration of the X-ray contrast medium, iohexol (Omnipaque) in a patient who had not previously received any X-ray contrast medium. The eruptions resolved in 7 days, leaving no residual lesions. When the patient was challenged intradermally with the same contrast medium 1.5 months after recovery, the same type of eruption developed 1 day after challenge. Histological examination of biopsies from positive skin test sites revealed the presence of a dermal infiltrate of lymphocytes. This case is another example of a late-onset adverse reaction to an X-ray contrast medium, mediated by specific T cells. The usefulness of intradermal skin testing for confirming the allergic nature of the reaction and for studying cross-reactivity pattern is emphasized.
authors.affiliation: Research and Development, Amersham Health, P.O. Box 4220 Nydalen, 0401 Oslo, Norway. cath.christiansen@amersham.com
authors.forename: Cath
authors.initials: C
authors.lastname: Christiansen
authors.forename: Sten
authors.initials: S
authors.lastname: Dreborg
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Pichler
authors.forename: Hege
authors.initials: H
authors.lastname: Ekeli
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage* / Q000009:adverse effects*; D003875:Drug Eruptions / Q000209:etiology; D005076:Exanthema / Q000139:chemically induced* / Q000175:diagnosis; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D012882:Skin Tests; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007472:Iohexol