[Anaphylactic shock following administration of lidocaine after negative skin test]

A rare case of sudden fatal anaphylactic shock is described in a 50 year-old woman after secondary lidocaine blockade to relieve lumbar pain (the first blockade was performed 4 days before by the same physician after the negative skin test). The patient had the history of multiple allergic reactions to drugs, pollen, home dust, and citrus fruits (repeated Quincke's oedema). In the preceding period, lidocaine was several time administered without side effects during out-patient visits to a surgeon and dentist. The signs of anaphylactic shock appeared within 2 min after injection of 4 ml of 2% lidocaine solution (no other injections were made between the two blockades). Comprehensive emergency measures had no effect. The diagnosis was confirmed at autopsy; microscopic study of soft tissues revealed mast cell degranulation and characteristic changes in internal organs. A literature review of anaphylactic shock symptoms is presented. The fulminant development of this condition after lidocaine administration may be regarded as a fatal coincidence of circumstances that could not be foreseen by the physician. Caution is needed when prescribing medications to polyallergic patients.