Department of Dermatology, University Hospital Essen, University of Duisburg-Essen, Hufelandstrasse 55, Essen, Germany.
Contact Dermatitis. 2011 Apr;64(4):196-202. doi: 10.1111/j.1600-0536.2010.01855.x.
p-Phenylenediamine (PPD) 1% in petrolatum has been shown in a prospective study to elicit late reactions in 1.5% of routine patch tests, which may be indicative of patch test sensitization.
To assess the frequency of late reactions to reduced PPD patch test concentrations.
In 1838 patients, PPD was tested at three concentrations (0.5% pet., group I; 0.4% pet., group II; and 0.35% pet., group III). Patch tests were read on D1 (D2) to D3 (D4); additional late readings were performed on D7, D14, and D21. Patients who were not able to return for all scheduled late readings were telephoned on D7, D14, and D21, and questioned about a reaction at the patch test sites.
Data of 1666 patients (1069 women and 597 men) were eligible. Late reactions were observed in 9 patients, 3 in group I (0.49%) and 5 in group II (0.63%). In 7 of 8 of the patients with late reactions, patch tests were applied for 48 hr. On retesting, 4 of 5 patients became positive at D2 or D3.
The occurrence of late reactions to PPD may be influenced by patch test concentration and duration. PPD 0.4-0.5% pet. may cause late reactions indicative of active sensitization.
前瞻性研究显示，1%对苯二胺（PPD）在凡士林中引起迟发型反应的比例为 1.5%，这可能提示斑贴试验致敏。
评估降低 PPD 斑贴试验浓度后迟发型反应的频率。
在 1838 例患者中，PPD 以三种浓度（0.5% pet.，I 组；0.4% pet.，II 组；和 0.35% pet.，III 组）进行斑贴试验。斑贴试验于 D1（D2）至 D3（D4）读取；在 D7、D14 和 D21 进行额外的迟发读数。对于未能按时返回所有预定的迟发读数的患者，于 D7、D14 和 D21 进行电话随访，并询问斑贴试验部位的反应。
1666 例患者（1069 例女性和 597 例男性）的数据符合条件。9 例患者出现迟发型反应，I 组 3 例（0.49%），II 组 5 例（0.63%）。在 7 例迟发型反应患者中，8 例患者的斑贴试验持续了 48 小时。再次检测时，5 例患者中的 4 例在 D2 或 D3 时呈阳性。
PPD 迟发型反应的发生可能受斑贴试验浓度和持续时间的影响。0.4-0.5% pet.的 PPD 可能引起迟发型反应，提示活性致敏。
