Background Atopic dermatitis (AD) is a chronic relapsing skin disease caused by the intervention of plural unspecific stimulation or specific allergens accompanied with cutaneous physiologic dysfunction. AD is one of the most common skin diseases which effects up to 20% of Children and 1-3% of adults in most of countries of the world. The data from a Chinese epidemiologic research shows the prevalence rate of AD is 10.9%in school-age adolescent and 15.3% in preschool children in 2010.