Brief communications Fixed drug eruption induced by mepivacaine Maria Josd Torres, MD, Juan J. Garcia, MD, Ana M. Del Carlo Moratinos, MD, Carmen Rondon, and Miguel Blanca M6laga, Spain Less than 1% of adverse reactions to local anes- thetics are allergic in nature? In particular, two types of immunologically mediated reactions to local anes- thetics are commonly described: (1) IgE-mediated reactions (Gell and Coombs type I) and (2) allergic contact dermatitis (Gell and Coombs type IV). Although extremely rare, IgE-mediated reac- tions do occur in response to both amide- and ester-group agents?, 3 They may be characterized by hives, angioedema, bronchospasm, rhinorrhea, or, in severe cases, by shock. Topical anesthetics are not only widely used but are also potent contact sensitizers. They produce more than 80% of the total allergic reactions to local anesthetics. 4 They are characterized by contact dermatitis. On the basis of limited patch testing data, it has been postulated that ester-group anesthetic agents cross-react with each other, but not with the amide-group agents. This postulate appears to hold true with regald to contact hypersensitivity but has never been adequately studied with regard to IgE-mediated hypersensitivity,s Fixed drug eruption is characterized by an iso- lated erythematous macular pruritic lesion. An acute phase is followed by desquamation and hyperpigmentation. The lesion usually appears in the oral or genital mucous membranes but occa- sionally arises on the face. With re-stimulation, lesions always appear in the same place. The agents usually involved are: phenolphthalein, tet- racycline, sulfonamides, barbiturates, and nonste- roidal antiinflammatory drugs. CASE REPORT We present a case of fixed drug eruption caused by mepivacaine. A 22-year-old woman had a personal his- tory of cholinergic rhinitis, and her mother had a history From the Allergy Section, Carlos Haya Hospital, Mfilaga, Spain. Reprint requests: Maria Jos6 ;Forres, MD, P.O. Box 6152, 29080-M~ilaga, Spain. J ALLERGY CLIN IMMUNOL 1995;96:130-1. Copyright © 1995by Mosby-Year Book, Inc. 0091-6749/95 $3.00 + 0 1/54/63285 130 of atopic asthma. She had, on four occasions after oral surgery, itching and violet erythema on the upper right buccal commissure, lower lips, left buccal commissure, and upper right eyelid. The lesions appeared 20 minutes after administration of Scandinibsa (mepivacaine NaC1) and had a maximum expression at 24 hours after injec- tion of the drug. The lesions disappeared 12 to 14 days later with desquamation, leaving a slight brownish hy- perpigmentation. The dose of drug administered was not known by the patient. Six months later, an allergy evaluation was undertaken. We developed an intradermal test with commercial Scan- dinibsa 2% S/A (Braun Medical SA). (Aqueous solution of mepivacaine 2% in NaC1 is a preparation that does not contain parabens.) We used 1:1 and 1:10 dilutions in saline solution, and 0.02 ml was injected (2 mg and 0.2 rag, respectively). Negative results were obtained. We then carried out a double-blind, placebo-con- trolled challenge test. We injected 0.2 ml (20 rag) of Scandinibsa subcutaneously. Twenty minutes later, the itching and erythema appeared in the same places and with the same characteristics as the patient had experi- enced on the previous four occasions. We administered dexchlorpheniramine 5 mg intramuscularly, 6-methyl- prednisolone 125 mg intramuscularly and deflazacort 30 mg orally on 2 consecutive days; and the lesions disappeared by the end of the second day. This treat- ment aborted the progression of symptoms. One week later, we carried out an intradermal test with commercial lidocaine 2% S/A, (Braun Medical SA). (Aqueous solution of lidocaine 2% in NaCI does not contain parabens.) We used 1:1 and 1:10 dilutions in saline solution with negative results. One month after the administration of Scandinibsa, we carried out a double-blind, placebo-controlled challenge test with another anesthetic. We injected commercial lido- caine in therapeutic doses subcutaneously, and the patient had no reaction. She has since tolerated lidocaine. DISCUSSION Preservatives are an integral component of most local anesthetic preparations. Parabens, including methylparaben and propyl paraben, are the preser- vatives most widely used. Because of concern that parabens may account for some allergic reactions, paraben-free preparations have become commer-