ABSTRACT
Benzocaine is a local anesthetic and the prototype of the PABA esters commonly used as a topical pain and itch reliever. It is the active ingredient in many over-the-counter analgesic ointments and anti-itch preparations, e.g. for insect bites, hemorrhoids and anal pruritus. Benzocaine, the ethyl ester of p-aminobenzoic acid, was the first synthetic local anesthetic, introduced into clinical practice as Anaesthesin in 1902. The high risk of sensitization to and allergic contact dermatitis from benzocaine has been well recognized for a long time and therefore, in recent decades, benzocaine has been gradually replaced with other less sensitizing local anesthetics such as lidocaine. Benzocaine has long been included in most routine patch test series in a concentration of 5% in petrolatum. As benzocaine is (or until recently was) present in most baseline/routine/screening/standard series tested worldwide, data on testing this local anesthetic in consecutive patients (routine testing) is abundant.
