Unidad de Alergología, Complejo Hospitalario de Jaén, 23007 Jaén, Spain.
Dermatitis. 2009 Nov-Dec;20(6):E13-5.
Ethyl chloride (EC) or chloroethane (C2H5Cl) is a volatile halogenated hydrocarbon. Reports of contact sensitivity to this gas are infrequent considering its widespread use as a local anesthetic, and it may have a relatively low sensitization potential. Benzocaine is another local anesthetic derivative of the ethyl ester of para-aminobenzoic acid, previously reported as a causative agent of delayed hypersensitivity reactions. We present a patient who developed a generalized itching dermatitis after the application of a medical aerosol containing EC, as well as facial angioedema and tongue swelling after the local application of benzocaine. Patch-test results were positive for EC "as is" (++), benzocaine 5% in petrolatum (++), and caine mix (+++) at 96 hours (day 4). The possibility of cross-sensitization between both drugs would not have been chemically plausible. We report the first published clinical case of contact allergic dermatitis from two chemically unrelated local anesthetics (EC and benzocaine) in the same patient.
氯乙烷（EC）或氯乙烷（C2H5Cl）是一种挥发性卤代烃。考虑到其作为局部麻醉剂的广泛应用，接触这种气体导致过敏的报道并不常见，而且它可能具有相对较低的致敏潜力。苯佐卡因是对氨基苯甲酸乙酯的另一种局部麻醉衍生物，以前曾被报道为迟发性超敏反应的致病剂。我们报告了一例患者，在使用含有 EC 的医用气雾剂后出现全身性瘙痒性皮炎，在局部使用苯佐卡因后出现面部血管性水肿和舌肿胀。斑贴试验结果在 96 小时（第 4 天）时对 EC“原样”（++）、凡士林中的 5%苯佐卡因（++）和卡因混合物（+++）呈阳性。两种药物之间的交叉致敏在化学上不太可能。我们报告了首例在同一患者中同时接触两种化学上不相关的局部麻醉剂（EC 和苯佐卡因）引起的接触性过敏性皮炎的临床病例。
