Mackenzie L A
Br J Dermatol. 1983 Jan;108(1):1-9. doi: 10.1111/j.1365-2133.1983.tb04572.x.
When the abnormality of a skin response to sunlight is expressed in terms of a decreased minimum erythemal dose (MED) on photo-testing, it is essential to know the range of response in normal skin. In any homogeneous population, the statistical distribution of the MED is skewed and is not Gaussian (normal), but a Gaussian distribution can be fitted to the logarithm of the MED. Using established methods of probit analysis, such 'lognormal' distributions have been fitted to the observed proportions of erythemal responses to a series of test exposure doses of UV radiation (250-365 nm), thus providing estimates of the average log MED for normal skin, the standard deviations of the distributions and associated confidence limits. These estimates, in arithmetical terms, are available for quantitative comparison with the results of other test exposures on skin which may be abnormal.
当皮肤对阳光的异常反应表现为光测试中最小红斑剂量（MED）降低时，了解正常皮肤的反应范围至关重要。在任何同质人群中，MED的统计分布是偏态的，不是高斯（正态）分布，但高斯分布可以拟合到MED的对数上。使用既定的概率分析方法，已将此类“对数正态”分布拟合到对一系列紫外线辐射（250 - 365纳米）测试暴露剂量的红斑反应观察比例上，从而提供了正常皮肤平均对数MED的估计值、分布的标准差以及相关的置信区间。从算术角度来看，这些估计值可用于与可能异常的皮肤其他测试暴露结果进行定量比较。
