The face suddenly swollen and itchy redness is mainly considered with contact dermatitis, acute eczema, urticaria, solar dermatitis and so on. 1. Contact dermatitis: when the facial skin is in contact with exogenous substances, such as cosmetics, hair dyes, etc., there may be a sudden swelling and itching and redness. 2. Acute eczema: the cause of the disease is still unclear, and it is mainly considered to be related to bad living habits, dietary habits, chemicals and other factors. Usually start faster, lesions are often manifested as erythema, corn size papules or small blisters, so acute eczema patients face will suddenly swollen and itchy red. 3. Urticaria: Urticaria is related to contact with allergenic substances, autoimmune decline, infection, mental factors. The main performance of the patient has wind, angioedema, itchy skin, etc., and some patients will appear face suddenly swollen and itchy red phenomenon. 4. Solar dermatitis: solar dermatitis will cause some patients to appear face suddenly swollen and itchy red, serious cases will appear blisters, skin erosion, flaking, hyperpigmentation and so on. Solar dermatitis is mainly related to long-term ultraviolet radiation. It is recommended that the face suddenly swollen and itchy red people to medical examination, in order to clarify the cause of the disease, and then follow the doctor’s instructions for treatment. For face swelling, itchy phenomenon, the patient can be relieved by local ice packs, do not scratch with your hands.