Blömeke Brunhilde, Pietzsch Tim, Merk Hans F
Department of Ecotoxicology and Toxicology, University of Trier, Am Wissenschaftspark 25-27, 54296, Trier, Germany.
Contact Dermatitis. 2008 Jun;58(6):355-8. doi: 10.1111/j.1600-0536.2008.01347.x.
Para-phenylenediamine (PPD) is an important and common cause of allergic contact dermatitis. The mechanism of sensitization is still unknown. It is believed that PPD is a prohapten and thus the balance between activation and/or detoxification processes may influence responses to PPD. Beside auto-oxidation to Bandrowski's base, PPD is enzymatically acetylated to monoacetyl-PPD (MAPPD) and to N,N'-diacetyl-PPD (DAPPD) in skin and keratinocytes.
We investigated if the 2 acetylated PPD derivatives are able to elicit allergic contact dermatitis by performing epicutaneous skin tests in subjects with dermatitis.
Contact allergy to PPD and the 2 acetylated derivatives (1% in petrolatum) were detected by patch testing of 455 patients with eczema from our clinic who were tested with the baseline series.
16 subjects were found to be patch test positive to PPD (3.5%). No reactions were found for MAPPD, and just 1 PPD-positive patient was positive for DAPPD (0.2%). In agreement with our earlier published in vitro data, these in vivo patch test results indicate that acetylation of PPD can be regarded as a detoxification reaction.
对苯二胺（PPD）是过敏性接触性皮炎的一种重要且常见病因。致敏机制尚不清楚。据信PPD是一种前体半抗原，因此激活和/或解毒过程之间的平衡可能会影响对PPD的反应。除了自动氧化生成班德罗夫斯基碱外，PPD在皮肤和角质形成细胞中还会被酶促乙酰化生成单乙酰-PPD（MAPPD）和N，N'-二乙酰-PPD（DAPPD）。
我们通过对患有皮炎的受试者进行皮内皮肤试验，研究这两种乙酰化的PPD衍生物是否能够引发过敏性接触性皮炎。
通过对我们诊所455例接受基线系列检测的湿疹患者进行斑贴试验，检测对PPD和两种乙酰化衍生物（凡士林基质中1%）的接触性过敏。
发现16例受试者斑贴试验对PPD呈阳性（3.5%）。未发现对MAPPD有反应，仅有1例PPD阳性患者对DAPPD呈阳性（0.2%）。与我们之前发表的体外数据一致，这些体内斑贴试验结果表明PPD的乙酰化可被视为一种解毒反应。
