Löffler H, Freyschmidt-Paul P, Effendy I, Maibach H I
Department of Dermatology, University of Marburg, Germany.
Am J Contact Dermat. 2001 Mar;12(1):28-32. doi: 10.1053/ajcd.2001.19602.
Test chambers for irritant patch testing are usually larger than those used in allergic patch testing. In general, larger areas show stronger skin reactions than smaller areas.
This study investigated whether this difference is of practical relevance, when a model irritant is applied in small and large Finn chambers and evaluated by measurement of transepidermal water loss (TEWL).
Patch testing was performed with 2 concentrations of sodium lauryl sulfate (SLS) (0.25% and 0.5%) on forearms of healthy volunteers. Large (inner diameter, 12 mm) and small (inner diameter, 8 mm) chambers were used.
A variance analysis (3 factors, 2-tailed) showed that the test outcome, as assessed by TEWL, was strongly dependent on SLS test concentration and test chamber size. The larger chambers gave approximately 30% to 50% higher values than the smaller.
This may be explained by the fact that with the small chambers, the adjacent small area of nontreated skin was also assessed by the evaporimeter, biasing the results. A formula estimating TEWL value of the large chamber from values of the small chambers has been proposed.
刺激性斑贴试验的测试室通常比过敏性斑贴试验使用的测试室大。一般来说，较大面积的皮肤反应比较小面积的更强。
本研究调查了在小芬氏小室和大芬氏小室中应用模型刺激物并通过测量经表皮水分流失（TEWL）进行评估时，这种差异是否具有实际意义。
在健康志愿者的前臂上使用2种浓度的十二烷基硫酸钠（SLS）（0.25%和0.5%）进行斑贴试验。使用大（内径12毫米）、小（内径8毫米）两种小室。
方差分析（3个因素，双侧）表明，通过TEWL评估的测试结果强烈依赖于SLS测试浓度和测试室大小。大测试室得出的值比较小测试室高约30%至50%。
这可能是因为使用小测试室时，蒸发仪也会测量相邻未处理皮肤的小面积，从而使结果产生偏差。已提出一个根据小测试室的值估算大测试室TEWL值的公式。
