A 22-year-old female with a questionable lidocaine allergy presented to her general dentist for a routine four-surface amalgam restoration on tooth 3. She had previously had other restorative work performed by this dentist. The lidocaine reaction first presented in her 6 months prior at a primary physician’s office in which she was having several moles removed. The physician told her she was allergic to lidocaine because she apparently had significant swelling all around the surgical site.
The patient claims she told her dentist of her reaction to lidocaine. Regardless, he then proceeded to inject 2% lidocaine with 1:100,000 epinephrine and began to prepare the tooth. Apparently the tooth needed root canal therapy and he then proceeded to perform a pulpectomy. The next day, day 2, the patient noticed mild unilateral swelling. The patient thought nothing of it since she was advised to expect mild swelling. The following day, day 3, the swelling intensified and she was told to apply ice until she could be seen later that day. Another dentist in the practice saw her, as an emergency, until the original dentist became available. She stated that she thought she was having an allergic reaction to the lidocaine. The partner then proceeded to perform an infiltration of 2% lidocaine with 1:100,000 epinephrine. The canals were cleaned and the tooth temporized and she was started on an antibiotic.
On day 4, the patient complained of intense and severe swelling; therefore, she was referred to an oral and maxillofacial surgeon. The surgeon examined her and advised her that she needed to have an incision and drainage (I and D) performed under local anesthesia. According to his records, he presumably performed the I and D with 2% lidocaine with 1:100,000 epinephrine. Although there was no pus present to confirm the preliminary diagnosis of an abscess, the surgeon nevertheless placed a drain and prescribed cephradine, demerol, and promethazine.
The next day, day 5, the swelling had become so severe her right eye had swollen shut (Figure 1). She was then admitted to the hospital. She was placed on intravenous clindamycin canadian and pain medications. Her laboratory results were within normal limits except for a slightly high white blood count (WBC) of 11.2 К (hospital norms were from 4.9 to 10.8 K).
Figure 1. Polaroid photograph taken on the fifth day after the reaction.
She spent the next day, day 6, in the hospital and was released on day 7 with intravenous clindamycin and home health care nursing. Her WBC had then decreased to 7.2 K. The day after being discharged, she was seen by her primary care physician, who prescribed (Allegra®), then soon changed her to oral clindamycin. Her primary care physician then performed testing on her forearm a few weeks later. He concluded she had an allergic response to the lidocaine solution he used to remove the moles. Allergy testing was performed again by the senior author to clarify whether the patient was allergic to the local anesthetic, the preservatives, or the antioxidant.
Figure 2. Right forearm at allergy testing: X, lidocaine with epinephrine containing metabisulfite; P, mepivacaine plain with no preservative; S, sterile saline control.
The method of testing was a modification of the dermal-nasal-optical technique previously described by Campbell and Giglio. The patient was advised of the complications of allergy testing and knowingly consented to the testing. After the placement of an intravenous access and appropriate monitoring equipment, testing was begun. With the use of a tuberculin syringe and a 25-gauge needle, selected agents were administered to the ventral surface of either forearm. The following agents were injected intradermally to produce a 5-mm diameter wheal approximately 3 inches apart on the right forearm: 2% lidocaine with 1:100,000 epinephrine from a dental cartridge, 3% mepivacaine plain from a dental cartridge, and saline plain. In the left forearm, the sole agent was lidocaine 2% plain from a multidose vial (Figures 2 and 3). After 45 minutes without the observation of any systemic reaction, a challenge dose of 1.8 cm3 of 2% lidocaine with 1:100,000 from a dental cartridge was given in the anterior mandibular vestibule. The anterior region was selected to allow for optimum observation as well as to confine any swelling, which may develop locally, to a region that would not compromise her airway. There was no immediate reaction to the skin testing or challenge dose within the first hour; therefore, the patient was released until evaluation the next morning.
Figure 3. Left forearm at allergy testing: X, no epilidocaine without epinephrine from a multidose vial containing methylparaben.