Poulsen L K, Liisberg C, Bindslev-Jensen C, Malling H J
Laboratory of Medical Allergology, National University Hospital, Copenhagen, Denmark.
Clin Exp Allergy. 1993 Jan;23(1):61-8. doi: 10.1111/j.1365-2222.1993.tb02485.x.
When skin-prick tests (SPTs) are used quantitatively, the circumference of the weal and/or the flare is outlined using a felt tip pen, and transferred to paper by adhesive tape. The aim of the study was to develop and validate a procedure, objectively and precisely determining these areas after transfer to paper. A system was developed enabling the drawing of the area of weal or flare to be read by a hand-held scanner and calculated on a personal computer. Areas in the 5-500 mm2 range could be determined with day-to-day and interoperator coefficients of variation (CVs) of 3.1% and 1.8%, respectively. Accuracy was determined in two ways: by correlation to cutting/weighing of four times enlarged SPT areas (r2 = 0.999, P < 0.001) and by measuring standardized areas (deviations less than intra-assay CV, i.e. 1-2%). For comparison, CV of alternative methods were also determined: eight different areas (9-76 mm2) were evaluated in quadruplicate using the SPT-scanner (CV = 1.4%), by cutting/weighing of paper (CV = 2.3%), by digitizing (CV = 4.4%) or by measuring longest and orthogonal diameters (CV = 13.6%). In conclusion, the scanning device and software provides an objective and reproducible procedure for rapid determination of SPT areas. When areas are determined by scanning, digitizing or cutting/weighing the variations in area determination becomes negligible compared to the variations of the entire skin test procedure.
当定量使用皮肤点刺试验（SPT）时，用毡尖笔勾勒出风团和/或红晕的周长，并用胶带转移到纸上。本研究的目的是开发并验证一种方法，在转移到纸上后能客观、精确地确定这些面积。开发了一种系统，可通过手持扫描仪读取风团或红晕区域的图形，并在个人计算机上进行计算。5 - 500平方毫米范围内的面积测定，日常和不同操作人员的变异系数（CV）分别为3.1%和1.8%。通过两种方式确定准确性：与四倍放大的SPT区域的切割/称重结果进行相关性分析（r2 = 0.999，P < 0.001），以及测量标准化区域（偏差小于批内CV，即1 - 2%）。为作比较，还测定了其他方法的CV：使用SPT扫描仪对八个不同面积（9 - 76平方毫米）进行四次重复评估（CV = 1.4%），通过纸张切割/称重（CV = 2.3%）、数字化（CV = 4.4%）或测量最长和正交直径（CV = 13.6%）。总之，扫描设备和软件为快速测定SPT面积提供了一种客观且可重复的方法。当通过扫描、数字化或切割/称重来确定面积时，与整个皮肤试验程序的变异相比，面积测定的变异可忽略不计。
