If your face is always allergic lately, consider whether you are often exposed to allergic factors, including the following: 1. strong and persistent exposure to sunlight. 2. recently changed cosmetics, especially those of unknown composition. 3. in dusty places or humid environments filled with dust mites and dust mites. 4. often eat spicy and irritating foods, including raw onions, raw garlic, chili peppers or often eat beef and mutton, seafood and such hairy products. 5. often eat ash and amaranth vegetables that tend to cause photosensitivity. 5, often eat ash, amaranth easy to cause photosensitive vegetables. During the period of allergy, you can take levocetirizine hydrochloride capsules orally once a day to prevent the occurrence of allergy.