Alleged allergy to local anaesthetic drugs.

OBJECTIVE

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

SETTING

University General and Dental Hospitals.

INTERVENTIONS

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.

RESULTS

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.

CONCLUSION

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