Iodine allergy: Common misperceptions

Disclaimer In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose The current evidence regarding iodine-containing compounds and iodine allergy cross-reactivity is reviewed. Summary Iodine is an essential human nutrient found in the thyroid gland. It is used in the synthesis of the thyroid hormones thyroxine and triiodothyroxine. Patients who report having adverse reactions to iodine-containing substances are often labelled as having an “iodine allergy,” which can result in delays in care or patients being denied essential ICM or other iodine-containing drugs. A literature review was conducted to evaluate the evidence regarding iodine allergy and iodine-containing drugs. Of 435 articles considered potentially appropriate for full review (plus 12 additional articles included on the basis of references from the eligible articles), 113 could not be obtained. After exclusion of 353 articles that did not meet all inclusion criteria, the remaining 81 articles were included in the review. The results of the literature review indicated that iodine has not been shown to be the allergen responsible for allergic reactions to iodinated contrast media, amiodarone, povidone-iodine, and other iodine-containing compounds. Conclusion There is a lack of evidence to support cross-reactivity between iodine-containing compounds in so called iodine-allergic individuals.