[Allergic reactions to local anesthetics].

In this article type I and type IV allergic reactions evoked by local anaesthetics are discussed. Contact dermatitis (type IV) reactions are mainly caused by local anaesthetics of the ester-type like procaine. Both contact dermatitis and anaphylactic reactions (type I) can be caused by anaesthetics of the amide-type (e.g. lidocaine), but these reactions are rare. Intra- and epicutaneous tests can be useful to prove allergy, but sometimes provocation tests are necessary. Many reactions are not caused by an allergic mechanism.