Redness, swelling and allergy on the face refers to contact dermatitis, which is an acute or chronic inflammatory reaction that occurs at the contact site of the skin mucosa after contact with certain exogenous substances. It should actively search for the cause of the disease and take general treatment or medication to reduce the swelling. 1. Finding the cause: Facial allergy is often caused by the use of cosmetics or skin care products containing allergenic substances, in addition, the environment, climate, diet and so on can also cause facial allergies. You should stop using cosmetics, allergy diet, and improve the environment. 2. General treatment: ice can be used to make facial vasoconstriction, relieve the symptoms of redness and swelling of the face; also need to eat a light diet, facial physical sunscreen to prevent aggravation of the condition. 3. medication: you can take oral antihistamines, such as loratadine and other treatment of redness and swelling; at the same time with the boric acid solution and other drugs external wet compresses, reduce facial itching; redness and swelling is obvious, you can use a weak glucocorticoid, such as mometasone furoate ointment. Appear face redness allergy, should be timely to the hospital treatment, under the guidance of the doctor for treatment, do not self-medication.