Video-nailfold-microscopy and local cold test: morphological and hemodynamic correlates in 124 healthy subjects.

Video-nailfold-microscopy in combination with a local cooling test were used to determine morphological and hemodynamic reference values with their variabilities such as sex, age, blood pressure and smoking habits in 124 healthy volunteers. In our non-smoking population (n = 90) neither arterial blood pressure nor age or the sex of the subjects had any significant influence on the morphological or hemodynamic parameters, even after the local cooling test. However, cooling the skin caused in all cases a rapid, temporary decrease in the velocity of blood flow through the capillaries. The small group of chronic smokers (n = 34) showed no sex differences in any of the measured variables even when compared with sex and age matched non-smokers. It may be concluded that video-capillaroscopy, a non-invasive technique, can be used in clinical practice for studying the physiology and pathophysiology as well as the dynamic response to local cooling in microcirculatory diseases of the human skin.