Anaphylactic reaction to hydroxyzine in an anesthetized patient.

A case of anaphylaxis occurring during a general anesthesia is presented. The reaction was severe with bronchospasm and hypotension (grade 2 in the severity of per-operative anaphylactic shock). The responsibility of hydroxyzine, administered for premedication was suspected by intradermal testing with the molecule, which was twice positive at a 10(-2) dilution of the commercial solution. The same test remained negative in 5 control subjects. All the other drugs received during anesthesia gave negative results. Using the same protocol excepted for the use of hydroxyzine a new general anesthesia could be performed under a premedication with dexchlorpheniramine without any allergic reaction. Anaphylactic reactions are very rare with hydroxyzine used in premedication for anesthesia in regard to the large prescription of the drug. Only two previous cases were reported but attention of the allergist must be also pointed towards the medications received in the perioperative period as for the anesthetic drugs.