{"doi":"10.1016/j.jacig.2025.100543","title":"Intravenous iron reactions: Insights from an allergy and immunology perspective","abstract":"Background: Diagnosis and management of intravenous iron reactions is often challenging, as skin testing has unproven utility and most reactions are non-IgE-mediated. Objective: We aimed to identify clinical patterns and tolerability predictors in patients with reactions to intravenous iron. Methods: We conducted a retrospective cohort study of patients with reactions to intravenous iron who were referred to the Vanderbilt University Medical Center Drug Allergy Clinic from April 2014 through January 2025 and administered a follow-up survey via RedCap to evaluate patient outcomes with future intravenous iron administration. Results: Of the 51 patients presenting for adverse reactions to intravenous iron, 48 had skin testing performed. The skin testing results were deemed negative in all 48 cases (100%). Notable laboratory test results within 1 year of reaction were low vitamin D level (47%), high parathyroid hormone level (46%), and low phosphorus level (10%). Many patients (56%) were dermatographic, and their drug alert labels included opioids (31%), fluoroquinolones (14%), and radiocontrast dye (8%). Following assessment, 31 patients received intravenous iron (61%) using formulations that were the same as (n = 15 [48%]) and/or different from (n = 17 [55%]) the forumlation initially implicated, with the various modifications including antihistamines, slower infusion rate, and intravenous fluid pretreatment. Of these 31 patients, 27 (87%) tolerated the infusions. Additionally, following evaluation, the patients were surveyed regarding subsequent intravenous iron administrations, eliciting a 29% response rate (n = 15). Of the responders, 7 patients (47%) reported receiving intravenous iron after evaluation; all 7 reported tolerance. Conclusion: Most reactions to intravenous iron are non-IgE-mediated; however, our study introduces 2 novel observations, namely, a high frequency of dermatographism (56%) and common colabeling of these patients with drug alerts to Mas-related G protein-coupled receptor X2 (MRGPRX2)-activating drugs, suggesting a possible shared pathophysiologic mechanism.","journal":"Journal of Allergy and Clinical Immunology Global","year":2025,"id":526324,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":3,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9565,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":227961,"name":"Cosby A. Stone","orcid":"0000-0002-1888-4188","position":1,"is_corresponding":false},{"id":330885,"name":"Matthew S. Krantz","orcid":"0000-0001-7589-9127","position":2,"is_corresponding":false},{"id":106289,"name":"Elizabeth J. Phillips","orcid":"0000-0002-7623-3383","position":3,"is_corresponding":false},{"id":741752,"name":"Jordon Jaggers","orcid":null,"position":0,"is_corresponding":true}],"reference_count":12,"raw_metadata":null,"created_at":"2026-07-19T02:50:30.402772Z","pmid":"40832364","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}