Capillary dilation, commonly known as erythema, is a type of skin damage that occurs on the face or trunk area, mostly acquired, but some are congenital. In daily life, often see part of the facial skin red, and the naked eye can see a line of dilated capillaries, part of the red or purplish-red line, but also in the form of dotted, spotted or star-shaped damage, which is capillary dilation. The stimulation of temperature changes, long-term living in areas such as highlands, thin air resulting in lack of oxygen to the skin, wind, cold, heat and other harsher living environment factors, as well as the abuse of topical drugs, cosmetics, can cause capillary dilation. Usually capillary dilation, does not bring about serious organism damage.