Effect of the indoor environment on atopic dermatitis in children

Atopic dermatitis (AD) is a chronically relapsing inflammatory disorder of the skin. It is characterized by severe pruritus, sleep disturbance, and poor quality of life. In addition, AD frequently occurs in childhood and is considered the first manifestation of atopic march, which progresses into respiratory allergic diseases, such as asthma and allergic rhinitis, as the patient grow older. In this regard, the early diagnosis and active treatment of AD are required to lower the severity of disease and to prevent the development of atopic march. The proper management of AD includes avoidance of aggravating factors, barrier repair by skin care, and control of inflammation and infection with appropriate medications. Among them, identification and elimination of environmental risk factors responsible for worsening skin symptoms are essential. They include temperature, humidity, food and inhalant allergens, microorganisms, air pollutants, ultraviolet radiation, water hardness, and so forth. In particular, there is growing concern about indoor environment because time spent indoors and exposure to various kinds of pollutants is increasing with modernization and industrialization. In this review, we summarize the hazardous effect of temperature, humidity, cigarette smoke, volatile organic compounds, formaldehyde, and phthalates on the development or aggravation of AD. Current epidemiological studies and animal experiments suggest possible contributions of various indoor environmental factors to the development and aggravation of AD. However, further studies are needed to demonstrate a causal relationship between indoor environmental factors and AD.