Skin testing after anaphylactoid reactions to dental local anesthetics. A comparison with controls

Reactions to scratch and intradermal challenge with a variety of local anesthetics were examined in 90 patients and compared with 45 controls. The frequency of a positive scratch test was 13 of 90 in the patient group and 12 of 45 in the control group. Thus scratch testing did not appear to discriminate between test and control groups. Significantly greater numbers of patients (22 of 90) gave a positive intradermal response than controls (4 of 45) (chi-squared test p < 0.05). Nine patients showed reactions to more than one agent. The majority of reactions in both patients and controls were in atopic subjects (chi-squared test p < 0.05). In 87 of the 90 patients with suspected anaphylactoid reactions to local anesthetic agents, negative skin reactions to at least one of the agents allowed intrabuccal challenge and subsequent recommendation of an agent for future use. Skin testing, though not providing formal proof of allergy, provides a useful test to indicate local anesthetics that may be used for future procedures.