Allergy refers to the abnormal reaction of human immune system to a harmless substance, also known as allergic reaction. Patients often have allergic constitution, and the onset is related to common allergens in life, such as contact materials, food, inhalants, etc. At present, drug treatment can achieve clinical cure, but it often recurs after contact again. It is suggested that patients pay attention to 1 in their daily lives and avoid eating spicy food and seafood; 2. Avoid bathing in too hot water; 3, avoid scratching, so as not to aggravate the expansion of skin lesions, or cause secondary infection; 4. Don't treat yourself with drugs. Some drugs may contain hormones and have great side effects on the skin. You should go to a regular hospital in time and receive reasonable treatment.