Delayed urticaria caused by lidocaine in a child

Lidocaine is a commonly used local anesthetic for dental treatment. Urticaria caused by lidocaine has seldom been reported. Generally, urticaria immediately develops after exposure to a causative agent and is considered a manifestation of IgE-mediated hypersensitivity. However, delayed urticaria caused by local anesthetics was reported to be related to cell mediated hypersenstivity. A 3-year old girl visited our allergy clinic due to delayed urticaria after local administration of lidocaine. Both skin prick and intradermal tests with lidocaine revealed negative reactions. However, the provocation test with subcutaneous injection of lidocaine showed urticaria 7 hours after test. In order to identify alternative local anesthetic for the subsequent dental procedure, we performed skin prick, intradermal and provocation tests with procaine, a local anesthetic of the other class, all of which showed negative results. Therefore, we recommended procaine as an alternative local anesthetic, and the patient was successfully treated with procaine. To the best of our knowledge, this is the first case of delayed urticaria caused by lidocaine in Korea. (Allergy Asthma Respir Dis 2014;2:298-301)