Erythroderma is a facial phenomenon caused by the dilation of facial capillaries or the superficial location of some capillaries. The causes of its formation are: 1, primary mostly congenital genetic; 2, regional factors, such as plateau climate stimulation, and skin hypoxia resulting in an increase in the number of red blood cells, causing capillary dilation and rupture; 3, physical factors, such as cold, dry, sand, sun exposure, so that blood circulation is blocked, capillary tolerance exceeds the normal range, causing capillary dilation, rupture; 4, occupational factors, such as chefs, welding welders and other flame fumigation; 5, cosmetic care factors, such as the destruction of the ingredients of acid in skin care products, as well as skin immunity caused by peeling fragile, often on the beauty salon to do suction surface care can also lead to vasodilation rupture; 6, local or systemic disease complications caused by capillary dilation rupture; 7, long-term local use of corticosteroid drugs, causing capillary dilation, resulting in skin thinning, atrophy, etc.; 8. Sensitive skin is generally thin stratum corneum, they are sensitive to external sunlight, drugs, cosmetics, temperature (hot and cold), etc., resulting in un-slightly blood vessels when tight and loose, showing repeated bruising, causing blood vessels to meander and expand, resulting in the formation of red blood cells. The traditional methods for removing red blood cells include ultra-high frequency electrocoagulation therapy, Chinese herbal medicine therapy, topical cosmetic therapy, and topical anti-allergy cream therapy. There are also many misconceptions about erythema treatment, including: using external instruments can suck away erythema; using cosmetics and products can remove erythema; trying to eliminate erythema quickly. At present, photorejuvenation can be carried out for the treatment of erythema. The broad band spectrum of photons contains light that can be strongly absorbed by hemoglobin. When hemoglobin strongly absorbs light energy, it can damage the endothelial cells of blood vessels, coagulate and destroy blood vessels, and promote the restoration of the original contraction characteristics of blood vessels. Photoreduction of red blood cells requires multiple treatments, with an interval of 20-30 days each. The skin is sensitive and should be tried before using skin care products to avoid repeated allergies leading to aggravation or recurrence of erythema.