The number of dental patients experiencing hypersensitivity, including chronic hives, to topical antiseptics appears to be increasing, according to a study published in the Journal of Allergy and Clinical Immunology: Global.
Reports of povidone-iodine hypersensitivity appear to be lower, but efforts to improve patient safety may still be needed, the authors wrote.
“This study highlights a substantial rise in CHX-related hypersensitivity reports, emphasizing the need for heightened clinical vigilance,” wrote the authors, led by Dr. Ishitha Jagadish of the University of Arizona-Phoenix (J Allergy Clin Immun, November 20, 2025).
The study examined reports involving chlorhexidine (CHX) and povidone-iodine from the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS), a publicly available database that tracks the post-marketing safety of approved drugs. The database includes adverse event reports submitted by healthcare professionals, consumers, and manufacturers, they wrote.
The analysis focused on FAERS reports received from 2004 to 2024 for CHX and povidone-iodine products with at least 100 reported adverse events, including reaction types such as anaphylaxis, urticaria, and dermatitis. Of the reports in FAERS, 12,682 involved CHX and 3,033 involved povidone-iodine.
CHX reports included 5,989 cases of dermatitis (47%), 2,845 cases of urticaria (22%), and 450 cases of anaphylaxis (3.5%). Povidone-iodine reports were fewer, with 260 dermatitis cases (8.6%), 167 anaphylaxis cases (5.5%), and 65 urticaria cases (2.1%). Trend analysis showed rising CHX hypersensitivity reports, with urticaria increasing the most (incidence rate ratio [IRR]: 1.66), followed by dermatitis (IRR: 1.42) and anaphylaxis (IRR: 1.1), they wrote.
The rise in urticaria reports (instantaneous rate of change [IRO] ratio: 28,759.5) was much greater than increases in dermatitis (IROC ratio: 1,193.57) and anaphylaxis (IROC ratio: 6.55). In comparison, povidone-iodine showed less growth in dermatitis (IRR: 1.13, IROC: 11.67), anaphylaxis (IRR: 1.12, IROC: 9.52), and urticaria (IRR: 1.10, IROC: 6.80).
However, the study had limitations. FAERS lacked data on how many patients were exposed to CHX or povidone-iodine, limiting how well hypersensitivity risks can be interpreted, the authors added.
“Improving patient safety will require greater clinical awareness, routine assessment for prior sensitivities, and thorough evaluation following suspected reactions,” they concluded.
