Anaphylactoid reactions to local anaesthetics despite IgE deficiency: a case report.

The mechanisms involved in adverse reactions to local anaesthetic (LA) agents are poorly understood. True IgE-mediated reactions appear to be rare. We report a patient with panhypogammaglobulinemia who developed anaphylactoid reactions to two different LAs (lignocaine and procaine), associated with positive intradermal skin tests to these agents as well as prilocaine, despite absent detectable IgE in the serum and a negative RAST test to procaine. We conclude that direct histamine release induced by LA is likely to be the major mechanism in this case.