Vasoconstrictive effect of topical applied corticosteroids measured by laser doppler imaging and reflectance spectroscopy.

Topical application of corticosteroids induces blanching of the skin, based on changes of the underlying microcirculation of the skin. Usually the intensity of blanching after topical application of corticosteroids is measured subjectively by a trained observer using a visual score. In order to obtain an objective determination of the blanching effect and to assess the underlying effect of the skin perfusion, it is necessary to use noninvasive bioengineering techniques. The aim of this study was to compare changes in the vascular plexus during 72 h after topical application of corticosteroids of different potencies with control sites by two noninvasive techniques: laser Doppler imaging (LDI) and diffuse reflectance spectroscopy (DRS). We used the most potent vasoconstrictor, Clobetasol-di-propionate. After 8 h (1.49 Rm (mean reflectance) +/- 0.6 SEM) and after 30 h (0.52 Rm +/- 0.36) DRS showed significant changes in blood flow (during blanching and reactive hyperemia). LDI showed a slight change after 8 h (-0.04 aU (arbitrary units) +/- 0.02 blanching) and a second, significant reaction after 30 h (LDI: 0.18 aU +/- 0.04 reactive hyperemia). In LDI after 30 h higher values were found in men than in women (clobetasol-17-propionate under occlusion Deltat(30)-t(0) men: 0.47 aU +/- 0.18; n = 7; Deltat(30)-t(0) women: 0.14 aU +/- 0.02; n = 10; P = 0.025). This leads to the conclusion that DRS is of more value for the detection of blanching than LDI, which has its sensitivity in the hyperperfused skin. Measurement with both devices showed clear differences in men and women, which means that sex differences should be taken into account.