Half of the face is allergic to redness and itching, mainly related to half of the face contact with allergic factors, can be relieved by removing the triggers, local cold compresses, topical glycerite lotion, oral antihistamine treatment. 1. Remove triggers: If the patient is allergic to cosmetics of poor quality, avoid using them again, remove the triggering factors, reduce local irritation and improve the patient’s symptoms. 2. Local cold compresses: patients can wrap ice packs in towels and then apply cold compresses to the face, which can provide relief through continuous cooling. 3. Topical glycerine lotion: patients can also use glycerine lotion, can play the purpose of astringent and anti-itching, improve the patient’s symptoms. 4. Oral antihistamines: If the above measures are not effective, oral antihistamines such as loratadine and cetirizine can be added to the treatment. Half of the face appears allergic to the symptoms of redness and itching should be timely to the regular hospital, follow the doctor’s instructions standardized treatment, do not self-medication.