Cutaneous lidocaine allergy confirmed by patch testing.

A case is presented of a 55-year old woman who developed an eruption suggestive of contact dermatitis on repeated occasions after receiving anesthesia for dermatologic procedures. Patch testing revealed a positive reaction to lidocaine. Basic structures of anesthetics are reviewed, and the classification of immunologically-mediated allergic reactions is discussed. The presence of cutaneous lidocaine allergy has profound implications for the field of dermatology.