Singh S, Gupta A, Pandey S S, Singh G
Department of Dermatology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Dermatology. 1996;193(2):121-3. doi: 10.1159/000246225.
Patients often tell about reduced effectiveness of topical steroids on repeated use. Tachyphylaxis to these agents has been demonstrated in humans for vasoconstriction and histamine-induced wheal suppression in normal skin, but not in diseased skin. Relevance of these data to diseased skin is not clear. Further, the clinical impression does not appear to match tachyphylaxis shown in normal skin with regard to the time course.
To examine whether tachyphylaxis to histamine-induced wheal suppression by a topical steroid occurs in dermatitic skin and to determine its time course vis-à-vis normal skin.
Pharmacodynamic response to 0.05% clobetasol propionate applied daily under occlusion was measured by histamine-induced wheal suppression assay in 10 individuals. This test was performed on a steroid-treated normal site, on a steroid-treated site where dermatitis was induced by occlusive application of 40% croton oil, and on a vehicle-treated site in each individual at different intervals up to 14 days.
Suppression of wheal volume started from second day in steroid-treated sites. There was significant difference in the wheal volume in steroid treated normal vs. dermatitic sites from day 2 to day 10. Maximum wheal suppression occurred earlier in dermatitic skin (day 4 vs. day 6). After this, the volume of wheal started increasing and became equal to control (complete tolerance) on 12th day in dermatitic skin and on 14th day in normal skin.
Time courses of tachyphylaxis to the action of 0.05% clobetasol propionate were significantly different in normal skin and dermatitic skin. Complete tolerance occurred earlier in dermatitic skin compared to normal skin.
患者常诉说局部用类固醇反复使用后疗效降低。在人类中已证实，这些药物在正常皮肤中对血管收缩和组胺诱导的风团抑制会出现快速耐受，但在患病皮肤中则不然。这些数据与患病皮肤的相关性尚不清楚。此外，临床印象在时间进程方面似乎与正常皮肤中显示的快速耐受不相符。
研究局部用类固醇对组胺诱导的风团抑制在皮炎皮肤中是否会出现快速耐受，并确定其相对于正常皮肤的时间进程。
通过组胺诱导的风团抑制试验，在10名个体中测量了每天在封包下应用0.05%丙酸氯倍他索的药效学反应。该试验在每个个体的类固醇治疗的正常部位、通过封包应用40%巴豆油诱导皮炎的类固醇治疗部位以及赋形剂治疗部位，在长达14天的不同间隔时间进行。
在类固醇治疗部位，风团体积的抑制从第二天开始。从第2天到第10天，类固醇治疗的正常部位与皮炎部位的风团体积存在显著差异。皮炎皮肤中最大风团抑制出现得更早（第4天对第6天）。此后，风团体积开始增加，在皮炎皮肤中第12天、正常皮肤中第14天变得与对照相等（完全耐受）。
正常皮肤和皮炎皮肤对0.05%丙酸氯倍他索作用的快速耐受时间进程显著不同。与正常皮肤相比，皮炎皮肤中完全耐受出现得更早。
