Intraoperative allergic reaction to fentanyl: A case report.

Although rare, intraoperative allergic reaction can lead to significant morbidity and mortality. Clinical diagnosis is difficult as there is a need to differentiate from other causes of perioperative adverse reactions, such as side effects of administered drugs, or patients' medical conditions which may present with bronchospasm or hypotension. Intraoperative allergic reaction may be triggered by various agents. Among those, opioid-induced allergic reaction is scarcely reported. We report a case of a patient who has previously had allergic reaction to meperidine and intraoperatively showed fentanyl induced anaphylaxis or anaphylactoid reaction with literature reviews.