Alleged allergy to local anaesthetic drugs

To identify the true nature of an acute reaction in 25 patients initially diagnosed as allergic to local anaesthetic drugs.

University General and Dental Hospitals.

Detailed review of each patient's previous exposure to local anaesthetic drugs and of the history of the acute event was followed up with challenge testing by intradermal injection.

One patient was subsequently found to be genuinely allergic to a local anaesthetic drug of the amide type. A wide range of conditions had actually precipitated the other adverse reactions, but all could be classified under three major headings: an immunological condition to a different antigen; a manifestation of anxiety; or an iatrogenic problem.

Local anaesthetic allergy is rare, but does occur. All reactions to local anaesthetic drugs must be assessed carefully and specialist referral may be appropriate.