Prescreening intradermal skin tests cannot predict hypersensitivity reactions to iodinated contrast media

Published online: August 10, 2019

Hypersensitivity reaction to iodinated contrast media (ICM) is a persistent clinical issue due to widespread use of computed tomography (CT) examinations. Whether routinely performing intradermal skin tests (IDT) can predict hypersensitivity reactions is an unresolved question.

In a recently published article in The Journal of Allergy and Clinical Immunology: In Practice, Lee et al. reported the results of a prospective study evaluating the role of IDT as a screening test of hypersensitivity reactions to ICM. Fifteen (0.5%) of the 2,843 patients had a positive IDT result before their scheduled CT scan; however, none of these patients experienced a hypersensitivity reaction after administration of full-dose ICM. In contrast, nineteen patients who experienced hypersensitivity reactions after ICM challenge had a negative IDT result. The sensitivity and positive predictive value of IDT for ICM were both 0%.

In short, prescreening intradermal skin testing before CT imaging has no clinical value as a tool for predicting hypersensitivity reaction to ICM, and thus should not be performed routinely.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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