Hillen U, Jappe U, Frosch P J, Becker D, Brasch J, Lilie M, Fuchs T, Kreft B, Pirker C, Geier J
Department of Dermatology, University of Duisburg-Essen, Germany.
Br J Dermatol. 2006 Apr;154(4):665-70. doi: 10.1111/j.1365-2133.2006.07159.x.
Late patch-test reactions, developing at day (D) 7 or later have been described for several allergens. Late reactions may reflect patch-test sensitization. Para-phenylenediamine (PPD) and epoxy resins (ER) are potent allergens and therefore may potentially induce patch-test sensitization. Up to now, there has been no prospective study on the frequency of late reactions in routine patch testing with these allergens.
To assess the frequency of late reactions to PPD and ER.
PATIENTS/METHODS: In 1748 patients PPD (PPD-base, 1% pet.) and ER [based on diglycidylether of bisphenol A (DGEBA, 1% pet.)], and in 812 patients, nickel sulphate (5% pet.) were removed from the test panel of the standard series and applied on the medial side of the upper arm. Patch-test occlusion time was 24 h in 588 (PPD and ER) and 241 patients (nickel sulphate), respectively, and 48 h in 1160 (PPD and ER) and 571 (nickel sulphate) patients, respectively. Patch tests were read on D1-3 and D2-3, respectively; additional late readings were performed on D7, D14 and D21 after patch-test application. Patients who were not able to return for all scheduled late readings were telephoned on D7, D14 or D21, and questioned about a reaction at the test sites. Patients were instructed to perform daily self-examination from D4 onwards and to return immediately to the clinic if a reaction at the upper arm became visible.
Data of 1428 patients (ER and PPD) and 638 patients (nickel) were evaluable. In 25 patients (1.8%), patch tests became positive not before D7, among them 21 reactions to PPD (1.5%) and four reactions to ER (0.3%). In five of seven patients, repeated patch tests with PPD disclosed patch-test sensitization as the cause of the late reaction. All late reactions, except for one, occurred in patients in whom patch tests were applied for 48 h. No late reactions were seen with nickel sulphate.
PPD (1% pet.) elicited late reactions in 1.5% of routine patch tests, the majority of them probably being caused by patch-test sensitization. Therefore, the German Contact Dermatitis Research Group decided to remove PPD 1% pet. from the German standard series and to take efforts to optimize the patch-test conditions of PPD. One way to optimize PPD testing could be to reduce the exposure of PPD 1% to 24 h. Alternatively the patch-test concentration of PPD might be reduced.
多种变应原会出现迟发性斑贴试验反应，即于第7天或之后出现。迟发性反应可能反映斑贴试验致敏情况。对苯二胺（PPD）和环氧树脂（ER）是强效变应原，因此可能潜在地诱发斑贴试验致敏。到目前为止，尚无关于使用这些变应原进行常规斑贴试验时迟发性反应发生率的前瞻性研究。
评估对PPD和ER的迟发性反应发生率。
患者/方法：在1748例患者中，将PPD（PPD碱，1% 凡士林）和ER [基于双酚A二缩水甘油醚（DGEBA，1% 凡士林）]，以及在812例患者中，将硫酸镍（5% 凡士林）从标准系列的试验组中移除，并应用于上臂内侧。斑贴试验的封闭时间在588例（PPD和ER）和241例（硫酸镍）患者中分别为24小时，在1160例（PPD和ER）和571例（硫酸镍）患者中分别为48小时。斑贴试验分别在第1 - 3天和第2 - 3天读取结果；在斑贴试验应用后的第7天、第14天和第21天进行额外的迟发性结果读取。无法按计划返回进行所有迟发性结果读取的患者在第7天、第14天或第21天接受电话随访，并询问试验部位的反应情况。指导患者从第4天起每天进行自我检查，若上臂出现反应需立即返回诊所。
1428例患者（ER和PPD）和638例患者（镍）的数据可进行评估。在25例患者（1.8%）中，斑贴试验直到第7天才呈阳性，其中21例对PPD的反应（1.5%），4例对ER的反应（0.3%）。在7例患者中的5例中，重复进行的PPD斑贴试验表明斑贴试验致敏是迟发性反应的原因。除1例之外，所有迟发性反应均发生在斑贴试验封闭48小时的患者中。硫酸镍未出现迟发性反应。
PPD（1% 凡士林）在1.5%的常规斑贴试验中引发迟发性反应，其中大多数可能由斑贴试验致敏引起。因此，德国接触性皮炎研究小组决定从德国标准系列中移除1% 凡士林的PPD，并努力优化PPD的斑贴试验条件。优化PPD试验的一种方法可能是将1% PPD的暴露时间减少至24小时。或者也可以降低PPD的斑贴试验浓度。
