To crack a nut with a sledgehammer: premedication in a patient with a history of mild symptoms following the injection of a contrast agent

Numerous papers point to the fact that an “iodine allergy” does not exist (1-4). Nevertheless, patients and physicians still use this term. This can be problematic as shown in the following case report.

A female patient with aortic dissection type A acquired five minutes following the injection of the non-ionic iodinated contrast medium (ICM) iopromide a generalized itching, which disappeared without any treatment. During a period of 22 years, she regularly received 1 mg clemastine (Tavegyl^®) and 125 mg methylprednisolone (SoluMedrol^®) as intravenous premedication, because the index reaction (ICM-induced itching) has been documented in the electronic patient record RIS as “iodine allergy”.

Itching is a common adverse reaction following the injection of a contrast medium which does not harm the patient and which usually disappears without anti-allergy drug treatment. Without additional symptoms, itching is a so-called type A reaction (5). Itching with concomitant other symptoms such as urticaria, angioedema etc. is an alleged type B (hypersensitivity) reaction (5).

This case is both noteworthy, and of educational relevance because of the following facts.

First, the case is an example for a non-correct documented ICM-induced adverse reaction. Instead of “itching following the application of iopromide”, the electronic record mentions “iodine allergy”. As stated previously, the exact documentation is an important pre-requisite for effective prophylactic measures in future (6).

“Iodine allergy” is a problematic diagnosis, because this form of allergy does not exist (1-4). Consequently, an exact definition of this term is missing.

An adequate and rational prophylaxis based on a not existing diagnosis is impossible (7). Consequently, a drug pre-treatment by using a H1-blocker plus corticosteroid is an overtreatment with respect to the clinical symptom of the index reaction. Moreover, a premedication with H1-antihistaminic plus corticosteroid is more harmful than the mild symptom ‘itching’. Therefore, it is useful to consider other preventive measures such as omission of the culprit ICM, and application of a non-culprit agent (8).

Taken together, the presented case shows that regular education of both, radiologists and technical assistants is very important to ensure the correct documentation, and the correct diagnosis of ICM-related adverse reactions, for example. Moreover, the exact documentation/diagnosis is the prerequisite for a safe and adequate prophylaxis in patients at risk.

Acknowledgments

Funding: None.

Footnote

Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-22-256/coif). The author has no conflicts of interest to declare.

Ethical Statement: The author is accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Böhm I, Morelli J, Nairz K, Silva Hasembank Keller P, Heverhagen JT. Myths and misconceptions concerning contrast media-induced anaphylaxis: a narrative review. Postgrad Med 2017;129:259-66. [Crossref] [PubMed]
2. Beaty AD, Lieberman PL, Slavin RG. Seafood allergy and radiocontrast media: are physicians propagating a myth? Am J Med 2008;121:158.e1-4. [Crossref] [PubMed]
3. Böhm I, Nairz K, Morelli JN, Keller PS, Heverhagen JT. Iodinated Contrast Media and the Alleged "Iodine Allergy": An Inexact Diagnosis Leading to Inferior Radiologic Management and Adverse Drug Reactions. Rofo 2017;189:326-32. [Crossref] [PubMed]
4. Torres MJ, Trautmann A, Böhm I, Scherer K, Barbaud A, Bavbek S, Bonadonna P, Cernadas JR, Chiriac AM, Gaeta F, Gimenez-Arnau AM, Kang HR, Moreno E, Brockow K. Practice parameters for diagnosing and managing iodinated contrast media hypersensitivity. Allergy 2021;76:1325-39. [Crossref] [PubMed]
5. Rawlins MD, Thompson JW. Mechanisms of adverse drug reactions, In: Textbook of adverse drug reaction. New York: Oxford University Press, 1991.
6. Böhm IB, van der Molen AJ. Recommendations for Standardized Documentation of Contrast Medium-Induced Hypersensitivity. J Am Coll Radiol 2020;17:1027-8. [Crossref] [PubMed]
7. Lombardo P, Nairz K, Boehm I. Patients' safety and the "iodine allergy" - How should we manage patients with iodine allergy before they receive an iodinated contrast medium? Eur J Radiol 2019;116:150-1. [Crossref] [PubMed]
8. Abe S, Fukuda H, Tobe K, Ibukuro K. Protective effect against repeat adverse reactions to iodinated contrast medium: Premedication vs. changing the contrast medium. Eur Radiol 2016;26:2148-54. [Crossref] [PubMed]