Buckley D A, Basketter D A, Smith Pease C K, Rycroft R J G, White I R, McFadden J P
Contact Dermatitis Clinic, St John's Institute of Dermatology, St Thomas' Hospital, London SE1 7EH, UK.
Br J Dermatol. 2006 May;154(5):885-8. doi: 10.1111/j.1365-2133.2006.07170.x.
Cinnamal/cinnamic alcohol and isoeugenol/eugenol are pairs of related fragrance chemicals found in Fragrance Mix I (FM I), and thus are routinely tested in combination with other fragrances in the European standard patch test series. Their close structural similarity makes the occurrence of simultaneous sensitivity within these chemical pairs likely, although at present there are no robust data to support this hypothesis.
To establish the frequency of simultaneous reactions to these fragrance chemicals in patients with suspected fragrance allergy attending a contact dermatitis clinic; to provide evidence in support of proposed metabolic pathways; and to determine whether including all four separately in FM I is necessary to avoid missing a diagnosis of fragrance allergy.
We analysed retrospectively the records of patients patch tested to the European standard series during the 15-year period 1984-98 for positive reactions to FM I. In a subset of patients tested to the constituents of FM I, positive reactions to cinnamal, cinnamic alcohol, isoeugenol and eugenol were sought. Data were analysed using 2x2 contingency tables (Fisher's exact test).
During this period, 23,660 patients were tested to the European standard series, of whom 1811 (7.7%) had positive reactions to FM I. Of the 1112 patients tested to the constituents of FM I, 934 had positive reactions to at least one constituent (total 1324 positive reactions to constituents). Of these 934, 826 also had positive reactions to FM I itself; 108 were negative to FM I but reacted to one or more of its constituents. One hundred and seventy-eight patients did not react to any of the breakdown constituents of FM I; 34 of these had positive reactions to FM I itself. Of 139 patients allergic to cinnamic alcohol, 87 were also allergic to cinnamal (63%), compared with 108 (11.1%) of 973 cinnamic alcohol-negative patients (P<0.00001). Of 231 patients allergic to isoeugenol, 50 were also allergic to eugenol (22%), vs. 109 (12.4%) of 881 isoeugenol-negative patients (P=0.0002).
These data support in vitro experiments indicating that cinnamal and cinnamic alcohol may generate a common hapten and are consistent with the view that simultaneous sensitization to isoeugenol and eugenol occurs to a limited extent, despite their being metabolized via different pathways. In view of the substantial number of isolated reactions to each of these fragrance chemicals, all four should continue to be included separately as constituents of FM I.
肉桂醛/肉桂醇以及异丁香酚/丁香酚是香料混合物I（FMI）中发现的一对相关香料化学物质，因此在欧洲标准斑贴试验系列中，它们通常与其他香料一起进行测试。它们结构上的相似性使得这些化学物质对中同时出现敏感性反应成为可能，尽管目前尚无有力数据支持这一假设。
确定在接触性皮炎门诊就诊的疑似香料过敏患者中，对这些香料化学物质同时产生反应的频率；为所提出的代谢途径提供支持证据；并确定是否有必要在FMI中分别包含所有这四种物质以避免漏诊香料过敏。
我们回顾性分析了1984年至1998年这15年间接受欧洲标准系列斑贴试验患者的记录，以查找对FMI的阳性反应。在对FMI成分进行测试的患者亚组中，查找对肉桂醛、肉桂醇、异丁香酚和丁香酚的阳性反应。使用2×2列联表（Fisher精确检验）分析数据。
在此期间，23660名患者接受了欧洲标准系列测试，其中1811名（7.7%）对FMI有阳性反应。在对FMI成分进行测试的1112名患者中，934名对至少一种成分有阳性反应（对成分的阳性反应总计1324次）。在这934名患者中，826名对FMI本身也有阳性反应；108名对FMI呈阴性，但对其一种或多种成分有反应。178名患者对FMI的任何分解成分均无反应；其中34名对FMI本身有阳性反应。在139名对肉桂醇过敏的患者中，87名也对肉桂醛过敏（63%），而在973名肉桂醇阴性患者中，有108名（11.1%）过敏（P<0.00001）。在231名对异丁香酚过敏的患者中，50名也对丁香酚过敏（22%），而在881名异丁香酚阴性患者中，有109名（12.4%）过敏（P=0.0002）。
这些数据支持体外实验表明肉桂醛和肉桂醇可能产生共同的半抗原，并且与以下观点一致，即尽管异丁香酚和丁香酚通过不同途径代谢，但对它们的同时致敏在一定程度上会发生。鉴于对这些香料化学物质中的每一种都有大量的孤立反应，这四种物质都应继续分别作为FMI的成分包含在内。
