From diagnosis to desensitization in immediate hypersensitivity reactions to both oral and parenteral iron salts.

Background: Hypersensitivity reactions (HRs) to iron agents are increasing in parallel with increased use of iron preparations. Objective: We aimed to evaluate the clinical features and our previous desensitization protocol in patients with immediate hypersensitivity reactions (IHR) to iron agents. Methods: We screened the medical records of 96 patients with a history of IHRs to oral or intravenous (IV) iron agents. We evaluated clinical features and diagnostic test results. Furthermore, we assessed the safety and success rate of the desensitization protocol. Results: Forty-seven patients had a history of IHRs to oral iron preparations, whereas 49 patients had a history of IHRs to IV iron agents. Skin-prick tests (SPT) with suspected and alternative oral iron salts were performed in 52.1% of the patients, and five were positive. SPTs and intradermal tests with IV iron products were applied to 67.7% and 65.6% of the patients, respectively, and four yielded positivity. Anaphylaxis was more common in patients hypersensitive to IV iron agents (n = 33) (p < 0.001). In 15 patients for whom iron agents were mandatory, 52 successful desensitizations with ferric carboxymaltose were performed. Conclusion: Our study demonstrated that skin tests were not helpful in the diagnosis of IHRs to iron agents and the parenteral route of administration was related to more severe IHRs. Furthermore, in case of necessity, our IV desensitization protocol generated for ferric carboxymaltose is a safe, effective, and practical treatment of choice.