Facial allergy is a very common form of allergy that can manifest as itching of the face and may be accompanied by symptoms such as redness, papules, blisters, and oozing. Facial allergy is mainly an abnormal immune response due to the contact or entry of certain allergens into the body, which vary, such as food, drugs, etc. First, environmental factors too cold or too hot, sunlight, etc. can induce facial allergy. Long-term exposure to chemicals, irritating solutions, animal hair, etc. can aggravate the symptoms. Second, disease factors 1, dermatitis: including facial contact and allergic dermatitis. Both can be sensitized by skin contact with allergens, usually manifesting as itchy, polymorphic lesions with a tendency to fluid exudation; 2. Eczema: inflammatory skin reactions caused by a variety of factors, with a tendency to exude in the acute phase and rough and hypertrophic local skin in the chronic phase. The lesions are polymorphic, symmetrical, and prone to recurrence; 3, urticaria: due to some specific food, environmental changes, mood swings and other factors, resulting in the triggering of limited edema performance. Third, lifestyle hair dyes, cosmetics, perfumes, etc. can cause facial allergies. Fourth, drug factors cause allergies to more drugs, once the allergy needs to immediately stop the drug, promptly seek medical attention. Such as antibiotics, sedative-hypnotic drugs, antiepileptic drugs, antipyretic drugs, vaccines, etc., can cause systemic allergy and reflected in the face.