Urticaria induced by meperidine allergy

ALLERGIC reactions to narcotic analgesics are extremely rare (1±6). We report a case of generalized urticaria and angioedema after administration of meperidine. A 42-year-old woman was admitted to the emergency department with renal colic. The patient was treated intramuscularly with metamizole 2 g. One hour later, due to the persistence of pain, Dolantina (100 mg meperidine) was given intramuscularly. Within 15 min of the injection, she developed generalized pruritus, erythema, urticaria, facial angioedema, dysphagia, dysphonia, and dizziness. Physical examination showed laryngeal edema and generalized urticaria. Blood pressure was 110/70 mmHg. Immediate treatment with subcutaneous epinephrine and intravenous dexclorpheniramine and methylprednisolone resulted in a noticeable improvement after 2 h, enabling the patient to be discharged several hours later. Three months after the events described, and after the patient gave written consent, an allergy study was carried out. Skin tests were performed by prick tests and intradermal tests with metamizole, meperidine, and other narcotic analgesics, as described in Table 1. The skin tests were all negative except for the prick test with meperidine and morphine (Table 1). All concentrations employed were also skintested in a group of 10 controls subjects (two patients had allergic rhinitis, two chronic urticaria, and six urticaria during general anesthesia). All tests but the skin test with morphine proved to be nonirritant in this group. The skin prick test with morphine was also positive in seven controls. Commercial RAST for meperidine was not available. A single-blind, placebo-controlled oral challenge test with metamizole at a 2-g dose was negative. The patient did not consent to the meperidine challenge. The narcotic analgesics are among the most commonly administered drugs in hospitals. The most serious immediate adverse effect, respiratory depression, is a predictable effect related closely to analgesia. Although these drugs are potent histamine releasers, anaphylactoid reactions have rarely been described, and the antigenic safety of the drugs is impressive (1, 2). Levi & Rockoff (5) reported the ®rst case of true anaphylaxis developing after meperidine treatment in a child. They demonstrated the presence of speci®c IgE antibodies to meperidine by RAST. No controls were tested for this method, and skin tests with meperidine were not performed. We report a patient with immediate urticaria and angioedema induced by meperidine. The meperidine allergy was con®rmed by skin prick test. The negative result of this test in controls excluded the direct pharmacologic release of histamine at the tested concentration (50 mg/ml). There was no documentation of our patient having received meperidine previously, but its previous administration could have been unrecorded. Anaphylactic reactions to other narcotic analgesics (fentanyl and papaveretum) also have been reported (3, 4). Some authors have demonstrated the presence of an IgEmediated mechanism by positive skin tests or RAST to narcotic analgesics (3±6). Too few patients have been studied to determine accurately the likelihood of clinical crosssensitivity among narcotics. Possible crossreactivity among fentanyl, alfentanyl, sufentanyl, and meperidine has been suggested (6). Furthermore, after hapteninhibition studies with morphine, clear cross-reactivity was demonstrated with codeine, partial cross-reactivity was reported with meperidine and methadone, and no cross-reactivity was demonstrated with fentanyl, naltrexona, and bupremorphine (4). We could not demonstrate any cross-sensitivity to the other narcotics skin-tested in our patient. All skin tests with these agents were negative. The positive result of the prick test with morphine was considered to be nonspeci®c, Table 1. Skin-test response to narcotic analgesics