[Dermography in humans: dependence of skin vessel reactions on stimulus strength]

Application of measured skin stimulation (contrary to classic dermographism) revealed a microcirculation variety of changes and restoration (skin vessel selfregulation). The reaction phases were measured versus classic dermographism. The types of skin vessel reactions is found to depend upon the stimulus strength. The dynamics of pattern change of skin vessels is described to differentiate hatched zone (central) and surrounding ones. A tendency of appearing of the surrounding zone before the central those was found. Restoration of the microcirculation after skin stimulation (the period of vessel reaction disappearance) is detected by 3 factor relations: latency of appearance of the 1st phase reaction, phase quantity, and skin color. Dependence of parameters (vessel dilatation or constriction; pressure threshold evoking skin vessel reaction; latency of appearance and of restoration of the background color) is described to correlate with skin color (2nd, 4th, and 5th phototypes of the Fitz-Patrick classification).