In the center of the red lesion a small (1 mm) red papule is visible, surrounded by several distinct radiating vessels. Pressure on the lesion causes it to disappear. Blanching is replaced by rapid refill from the central arteriole when pressure is released.Source: M. Sand, D. Sand, C. Thrandorf, V. Paech, P. Altmeyer, F. G. Bechara / PMID 20525327