Chlorhexidine-Induced Contact Anaphylaxis.

Perioperative anaphylaxis is a rare but life-threatening event, with chlorhexidine increasingly recognized as a significant trigger. Though commonly used as an antiseptic due to its broad-spectrum antimicrobial properties, chlorhexidine can lead to sensitization through repeated exposure, resulting in both immediate and delayed hypersensitivity reactions. We report a case of severe perioperative anaphylaxis in a 72-year-old woman following abdominal surgery at the University Hospital of Besançon in May 2024. Chlorhexidine was used for preoperative skin antisepsis. Shortly after anesthesia induction with etomidate and rocuronium, the patient developed bronchospasm, followed by refractory hypotension and oxygen desaturation after administration of additional anesthetics. She required intensive care admission. Elevated acute serum tryptase (123 µg/L) confirmed anaphylaxis. Allergy investigations revealed positive skin tests and specific immunoglobulin E (IgE) to chlorhexidine, while tests for other agents were negative. Genetic testing excluded mast cell disorders or hereditary alpha-tryptasemia. Surgery was successfully completed five days later with chlorhexidine avoidance and no further reactions. This case underscores the potential severity of chlorhexidine-induced perioperative anaphylaxis. Given the widespread use of chlorhexidine and the possibility of delayed or underrecognized sensitization, clinicians must remain vigilant, particularly in patients with prior unexplained reactions. Preoperative screening and heightened awareness are essential to reduce morbidity and mortality associated with this increasingly reported allergen.