The causes of facial allergy are as follows: 1, contact allergy: if the allergic site is limited to the face, patients should consider contact etiology, commonly due to improper use of cosmetics or skin care products, resulting in skin erythema, itching and other symptoms; 2, sunburn allergy: frequent sun exposure can lead to itchy allergic symptoms on the face, neck, limbs and other exposed parts of the skin, or lead to the occurrence of eczema; 3, food allergy: consumption of certain foods that lead to allergies, such as seafood, alcohol, etc.