1, allergic constitution or allergic family history, to avoid all kinds of external stimuli, such as hot water scalding, scratching, sun exposure, etc., as far as possible to avoid allergic and irritating food. 2, life should be regular, pay attention to the combination of work and rest; more exercise, enhance their immunity. 3, clothing should be loose, to reduce friction stimulation, do not make chemical fiber and woolen fabrics directly contact the skin. 4, maintain good hygiene habits, change clothes regularly, keep the skin clean, avoid washing the affected area with hot water, soap and other irritating detergents, try to avoid scratching the local affected area with your fingers, and maintain emotional stability, do not be anxious, depressed. 5, diet should be light and nutritious, avoid eating fishy hair and fishy spicy food, such as wine, tobacco, mutton, beef, fish, shrimp and other foods. Keep your bowels open and get enough sleep.