Department of Dermatology and Allergy, Ludwig Maximilian University, Frauenlobstr. 9-11, 80337, Munich, Germany,
Curr Allergy Asthma Rep. 2013 Oct;13(5):539-44. doi: 10.1007/s11882-013-0368-6.
The atopy patch test (APT) is defined as a patch test procedure to assess delayed type hypersensitivity reactions against those protein allergens known to elicit IgE-mediated type I reactions in atopic patients. This patch test procedure uses intact protein allergens instead of haptens in an optimized test setting and with a special reading key. It may be clinically useful especially for atopic dermatitis, as the currently available test procedures either target the wrong reaction type (type I and not type IV) or use the wrong allergens (haptens and not protein allergen). A positive APT reaction correlates with a positive lymphocyte transformation test and allergen-specific Th2 cells in the peripheral blood. As even small changes in the test procedure influence the sensitivity, specificity, and reproducibility of the APT, the European Task Force on Atopic Dermatitis (ETFAD) has developed a standardized APT technique: Intact protein allergens, purified in petrolatum, are applied in 12-mm-diameter Finn chambers mounted on Scanpor tape for 48 h to non-irritated, non-abraded, or tape-stripped skin of the upper back for 48 h; the evaluation of the test reaction is done after 48 and 72 h using the ETFAD reading key, assessing erythema as well as number and distribution pattern of the papules. The APT may reveal type IV sensitization in patients who are negative for the respective type I tests. Limited availability of the expensive test substances and limited reimbursement is among the factors restricting the routine use of the APT.
变应原斑贴试验（APT）定义为一种斑贴试验程序，用于评估对那些已知在特应性患者中引起 IgE 介导的 I 型反应的蛋白质过敏原的迟发型超敏反应。这种斑贴试验程序使用完整的蛋白质过敏原而不是半抗原，并在优化的试验设置和特殊的阅读关键中使用。它在特应性皮炎方面可能具有临床意义，因为目前可用的测试程序要么针对错误的反应类型（I 型而不是 IV 型），要么使用错误的过敏原（半抗原而不是蛋白质过敏原）。APT 阳性反应与外周血中的淋巴细胞转化试验和过敏原特异性 Th2 细胞阳性相关。由于即使是测试程序中的微小变化也会影响 APT 的敏感性、特异性和可重复性，因此特应性皮炎欧洲工作组（ETFAD）已经开发出一种标准化的 APT 技术：完整的蛋白质过敏原，在凡士林中纯化，以 12 毫米直径的 Finn 室应用，安装在 Scanpor 胶带，用于 48 小时非刺激性、非擦伤或胶带剥离的上背部皮肤，48 小时后使用 ETFAD 阅读关键评估测试反应，评估红斑以及丘疹的数量和分布模式。APT 可能会在对相应的 I 型测试呈阴性的患者中揭示 IV 型致敏。昂贵的测试物质的有限可用性和有限的报销是限制 APT 常规使用的因素之一。
