Allergies lead to facial redness, mostly due to contact with certain substances or cosmetics, causing facial skin allergy. Common facial redness, itching, rash and other symptoms, need to be treated according to the cause of allergy. 1, contact with certain substances: some patients face contact with special substances will appear allergic reactions, such as dust, cosmetics, etc. Dust allergy patients can use cold water or refrigerated saline, boric acid solution, such as wet compresses red parts to relieve, go out to wear a mask to avoid secondary contact with allergens caused by recurrence. Cosmetic allergy patients need to immediately clean the face with warm water and use medical moisturizing cream under the guidance of a doctor, which can generally subside in about half an hour; 2, food factors: caused by eating allergenic foods, such as fish, shellfish, peanuts, nuts, etc. It is generally recommended that patients immediately stop eating foods that may cause allergies, conduct allergen tests, and avoid secondary feeding; 3, drug factors: some patients are prone to allergies to drugs, such as Penicillin, aspirin, etc. In this case, it is necessary to stop taking medication immediately and choose suitable alternative medication under the guidance of a doctor; 4. Physical factors: Some patients are sensitive to temperature changes and prone to allergic reactions, such as cold and heat stimulation, so it is recommended that patients try to keep the temperature constant and avoid large temperature differences. In addition, if the allergic symptoms are serious, with rice-like papules and itching symptoms, oral anti-allergy drugs, such as cetirizine, loratadine, levocetirizine, etc., and depending on the severity of the disease, oral glucocorticoids can be taken. Try to avoid the external use of hormonal ointments, which may cause hyperpigmentation, erythema, acne and other undesirable conditions. Before the allergy symptoms subside, the diet should be light, avoiding tobacco, alcohol, spicy stimulating and allergenic food to avoid aggravating the symptoms, and stay away from allergens after healing.