Atopic dermatitis is a chronic skin disease with atopic family history (asthma, rhinitis) and signs, manifested as itchy rashes on specific parts of the body, which have their own characteristics in various periods. 1. Infancy: the first lesions of children are itchy erythema on the cheeks, then pinpoint-sized papules and papules may occur on the basis of the rash, which are dense in patches and have unclear boundaries, and may rapidly expand to other parts of the body, and may form vesicles, oozing and scabs after scratching and friction, and may become infected secondary to the rash, and usually get better at the age of less than two years. 2. Childhood: Most of them are reoccurring and gradually aggravated by atopic dermatitis in infancy, and a few of them are continuing from infancy. The itching is severe, and the lesions usually occur on the flexion or extension of the limbs, mostly confined to the elbow fossa and popliteal fossa, and to a lesser extent on the eyelids, face and neck. The skin lesions are dark red in color and may be accompanied by secondary lesions such as scratches, which may form mossy lesions over a long period of time. 3. Young adults: it occurs in the elbow, popliteal fossa, limbs and trunk, etc. A few patients have more obvious palmoplantar areas, itching is intense, and there may be scabs or hyperpigmentation and other skin lesions after scratching. There may also be limited mossy changes or acute or subacute eczema-like changes, and there may be generalized dry papules. It is recommended that patients suffering from atopic dermatitis consult the dermatology department of regular hospitals for professional treatment.