[Chlorhexidine anaphylaxis in a perioperative context: diagnosis and management]

During surgery, the patient is exposed to multiple medications and molecules that can be associated with the development hypersensitivity, which makes it difficult to detect the causative agent of a perioperative reaction and makes it necessary to perform allergy tests.

53-year-old man who after a right knee arthroscopy was administered intravenous ketorolac; at 12 minutes, a pruriginous rash appeared on the chest, abdomen and limbs; infusion of the drug was immediately stopped and 100 mg intravenous hydrocortisone were administered. At 15 minutes, the patient experienced bilateral angioedema of the eyelids and a sensation of breathlessness, and oxygen was therefore administered, as well as 2 mg intravenous clemastine, 5 mg intravenous ranitidine and 20 µg subcutaneous adrenaline. Epidermal tests with 0.5 % chlorhexidine and serum chlorhexidine-specific immunoglobulin E (IgE) were performed, both with positive results. The patient recovered without complications; at discharge, he was prescribed intramuscular etofenamate.

Perioperative anaphylaxis is a rare, but potentially fatal event. Proper identification of the drug or substance responsible for the reaction by using allergy tests decreases unnecessary pharmacological restrictions and avoids re-exposure.