The causes of redness of the face are mainly related to long-term sun exposure, facial and neck follicular erythema nigra, allergic dermatitis, hormone-dependent dermatitis. 1. People who work outdoors for a long time or people in high latitude areas are prone to redness because they receive more sunlight. This is due to the thermal effect of sunlight, which will cause blood flow in the face to accelerate the expansion of capillaries. This kind of redness has no effect on the body and is usually not uncomfortable. Nervousness, emotional excitement, drinking alcohol can also cause a transient redness, which is caused by physiological factors. 2. Erythema Nigricans is a hereditary skin disease, which is also related to vitamin A deficiency. The main symptom is a rash like goose bumps on the arms and thighs, and the skin on the face and cheeks is rough and red, usually without discomfort. The disease can last a lifetime, and the symptoms will be relieved in old age. 3. Allergic dermatitis is mainly a localized allergic reaction caused by the contact of the facial skin with pollen, dust and other allergens, manifested as symmetrical redness of the facial skin, goose bumps, accompanied by a pronounced itching sensation. 4. Long-term use of skin care products with hormones, drugs, will make the skin thinning and atrophy, the emergence of flushed spots, red spots will have expansion of red blood, at the same time there will be itching burning and other discomforts, which leads to hormone-dependent dermatitis occurs. The redness of the face caused by the disease is best to go to the hospital in time to find out the cause of the disease, and for the cause of the medicine.