Local anesthetics (LAs) are frequently used in many branches of medicine, especially in dentistry and surgery, allowing to carry out safe and painless procedures without the need for general anaesthesia. Chemically local anaesthetics are grouped into two categories – derivatives of amide and derivatives of ester. Although these drugs are usually well-tolerated, they can sometimes provoke adverse reactions of various types and severity.

Adverse reactions after use of LAs are associated usually with intravenous administration, use of toxic doses, hypersensitivity reactions or psychogenic reactions. In spite of their widespread use, true IgE-related allergy appears to be very infrequent (less than 1% of all adverse reactions) and they are
a type I or IV hypersensitivity reaction, according to Gell and Coombs.

Skin tests for allergy, including skin-prick tests and intradermal tests, may have   poor sensitivity and specificity and the true incidence of local anesthetics allergic reactions  is unknown so it is appropriate to evaluate the incidence of any immediate adverse events after local anesthetics intake and to assess the relationship between the adverse reactions to other substances included in solutions of the local anesthetics, for example conservants.