Eczema is a big concept and atopic dermatitis is a relatively small concept, a specific eczema, mainly with a family history of allergy. Atopic dermatitis is relatively severe, with a long course and different rash manifestations at each age, and can be associated with increased immunoglobulin IgE, allogeneic protein allergy, and increased eosinophilia. The etiology of atopic dermatitis is related to genetics, environment, immune abnormalities, and the function of the skin barrier. It is mainly due to the genetic allergy itself combined with the stimulation of external environmental factors that stimulate the allergic immune response in the body. If both parents have allergic diseases, such as eczema, asthma, allergic rhinitis, and allergic conjunctivitis, the chances of the child getting atopic dermatitis are about 70%, and if one parent has allergic diseases, the chances of the child getting the disease are about 50%. The more developed countries are, the higher the incidence of atopic dermatitis. Nowadays, many foods contain many additives and preservatives; also, environmental pollution such as car exhaust, benzene and formaldehyde volatilized from renovated houses can trigger allergic reactions. Atopic dermatitis patients have defective skin barrier function, generally manifested as dry skin and reduced natural moisturizing factors; atopic dermatitis also has defective immune function, manifested as increased IgE, accompanied by food allergy or inhalant allergen sensitization, common food allergens such as milk, eggs, peanuts, fish and shrimp; inhalant allergens such as dust mites, fungi, pollen, cat and dog fur dander.