Current research confirms that allergic diseases are a class of immune diseases that are influenced by polygenic genetic and environmental factors. If the mother alone is allergic, the children have a 50% probability of inheritance; if the father alone is allergic, the children have a 30% probability of inheritance; however, there are also allergic children who appear within the range of brothers, sisters, grandparents, uncles and parents, and cousins. In addition, in addition to genetic background, some children exhibit a variety of allergic symptoms shortly after birth. Later, as they grow older, other allergic symptoms will gradually appear, such as eczema in infancy or recurrent diarrhea due to milk allergy, and then allergic cough, allergic asthma, allergic rhinitis after the age of 3. This process is called the “allergic process”. Studies have also shown that hereditary allergic reactions often occur not only in one organ, but in multiple tissues and organs simultaneously or sequentially. Therefore, different allergic reactions can occur at different ages.