Taylor J S, Praditsuwan P, Handel D, Kuffner G
Department of Dermatology, Cleveland Clinic Foundation, Ohio, USA.
Arch Dermatol. 1996 May;132(5):515-8.
Several topical antihistamines are known to cause contact allergy. Premarket predictive patch testing with doxepin cream showed it to have "low risk of irritation and sensitization" on normal human skin. In our patch test clinic, we routinely test topical preparations, and over a recent 1-year period, we patch-tested doxepin cream, the standard screening tray, and other topical preparations on 97 patients with various pruritic dermatoses. When possible, patients with positive reactions to doxepin cream were patch-tested with its ingredients, and repeated open-application use tests were also performed with the product.
Seventeen patients had relevant positive patch test reactions to doxepin cream and 80 had negative reactions. In 13 of the 17 patients with positive reactions, the diagnosis of allergic contact dermatitis to doxepin cream was confirmed by positive patch test reactions to both the active ingredient and the whole formulation of doxepin cream, by an observed positive use test reaction to doxepin cream, or by both. Of 14 patients who completed testing with doxepin cream ingredients, all had positive reactions to the whole formulation, and 12 had positive reactions to doxepin hydrochloride. Repeated open-application use tests with doxepin cream on normal skin resulted in positive eczematous responses in eight of 10 patients. Eight of the 17 patients had concurrent, relevant positive reactions to other patch tests, especially to fabric-finish resins and to ingredients of other topical preparations. Many had long-standing dermatitis, and each had used doxepin cream for several days to 1 year. Two patients appeared to have had systemic contact dermatitis.
Diagnostic patch test clinic experience illustrates that doxepin cream is a contact sensitizer on inflamed skin. Oral doxepin should be avoided in patients with doxepin contact allergy.
已知几种外用抗组胺药可引起接触性过敏。多塞平乳膏上市前的预测性斑贴试验表明，其在正常人体皮肤上“刺激和致敏风险较低”。在我们的斑贴试验诊所，我们常规检测外用制剂，在最近1年期间，我们对97例患有各种瘙痒性皮肤病的患者进行了多塞平乳膏、标准筛查托盘及其他外用制剂的斑贴试验。尽可能对多塞平乳膏反应阳性的患者用其成分进行斑贴试验，并用该产品进行重复开放应用试验。
17例患者对多塞平乳膏有相关阳性斑贴试验反应，80例为阴性反应。在17例阳性反应患者中的13例中，对多塞平乳膏活性成分和整个制剂的阳性斑贴试验反应、对多塞平乳膏观察到的阳性应用试验反应或两者均证实了对多塞平乳膏的过敏性接触性皮炎诊断。在14例完成多塞平乳膏成分检测的患者中，所有患者对整个制剂均有阳性反应，12例对盐酸多塞平有阳性反应。在正常皮肤上对多塞平乳膏进行重复开放应用试验，10例患者中有8例出现阳性湿疹反应。17例患者中有8例对其他斑贴试验同时有相关阳性反应，尤其是对织物整理树脂和其他外用制剂的成分。许多患者有长期性皮炎，且每人使用多塞平乳膏数天至1年。2例患者似乎发生了系统性接触性皮炎。
诊断性斑贴试验诊所的经验表明，多塞平乳膏在炎症皮肤上是一种接触致敏剂。对多塞平接触过敏的患者应避免口服多塞平。
