Allergy is also known as atopy, and people with atopy have been known to have allergic reactions and suffer from diseases such as dermatitis and food and drug allergies. People with atopic symptoms have increased airway reactivity and are prone to asthma and other wheezing diseases. The national epidemiological survey of pediatric asthma shows that 62.2% of children with asthma have a personal history of allergic diseases, which shows that asthma is very closely related to atopy. Atopic people have the following characteristics: 1, their airways are particularly sensitive to stimuli, healthy people exposed to certain stimuli may not have any reaction, but atopic people can cause asthma attacks. For example, dust mites, pollen, animal feathers, leather shawls, etc., and even cold air, smoke, respiratory infections, sports mental stimulation can cause asthma attacks. 2, they are prone to allergic diseases, such as eczema, allergic rhinitis, urticaria, drug and food allergies. 3, atopic stress is related to heredity, people with atopic stress have a high positive rate of asthma in their family history. 4, infants and young children are mostly fat body type, easy to suffer from respiratory and digestive tract infections. 5, IgE in serum is mostly elevated, peripheral blood eosinophils are elevated, while secretory IgA in respiratory secretions is mostly low, and immune dysfunction exists. 6.Higher rate of positive allergen test.