Local anesthetic hypersensitivity: Frequently suspected, rarely proven: A retrospective study of 101 patients.

Introduction

Local anesthetics (LAs) are commonly used to provide regional insensitivity in dentistry, minor surgical procedures, and general anesthesia but may rarely cause allergic reactions.

Methods

The file data of 101 patients who were referred to the Department of Allergy and Immunology, Ege University Faculty of Medicine, with a suspected LA allergy between February 2020 and August 2024 were retrospectively reviewed. Patients included in the study were contacted by phone and asked whether they had used LAs after the test and whether any reactions had developed.

Results

Female patients comprised 81% (n = 82) of the study cohort. Patients were predominantly referred from the departments of dentistry (45% [n = 46]) and anesthesiology (22% [n = 22]). Patients were referred due to reactions related to LAs alone (n = 51) and both LAs and other drugs (n = 50). The severity of LA reactions was mild (n = 47), moderate (n = 36), or severe (n = 18), with dyspnea being the most common symptom (n = 47). Prick-intradermal (P-ID) and provocation tests were performed on all the patients (suspected LAs [n = 32], alternative LAs [n = 23], random [n = 46]). Only one patient tested positive in the P-ID test, and a provocation test was performed on this patient with an alternative agent, with a negative result. Of the 80 patients reached by phone, 41 received LAs based on test results and did not develop an allergic reaction, whereas the other 39 patients did not receive LAs.

Conclusion

Immunologically mediated reactions to LAs were exceedingly rare in this study. These findings highlight that most suspected reactions are not attributable to confirmed allergic mechanisms and underscore the importance of a careful clinical history and guideline-based evaluation to avoid unnecessary drug avoidance.