Anaphylaxis caused by neostigmine.

A patient developed anaphylaxis during anaesthesia, towards the end of surgery, 30 s after intravenous administration of neostigmine. Anaphylaxis to neostigmine was confirmed by demonstrating an elevated mast cell tryptase and a strongly/positive skin prick test, showing the presence of drug-specific IgE (skin prick tests to neostigmine were negative in normal subjects). This is a rare cause of anaphylaxis during anaesthesia.