RT Journal Article
SR Electronic
T1 Association of the incidence of atopic dermatitis until 3 years old with birth month and with sunshine duration and humidity in the first 6 months of life: Japan Environment and Children’s Study
JF BMJ Open
JO BMJ Open
FD British Medical Journal Publishing Group
SP e047226
DO 10.1136/bmjopen-2020-047226
VO 11
IS 7
A1 Yokomichi, Hiroshi
A1 Mochizuki, Mie
A1 Tsuchida, Akiko
A1 Kojima, Reiji
A1 Horiuchi, Sayaka
A1 Ooka, Tadao
A1 Akiyama, Yuka
A1 Miyake, Kunio
A1 Otawa, Sanae
A1 Shinohara, Ryoji
A1 Inadera, Hidekuni
A1 Yamagata, Zentaro
A1 
YR 2021
UL http://bmjopen.bmj.com/content/11/7/e047226.abstract
AB Objective To compare the incidence of atopic dermatitis in children aged from 6 months to 3 years across birth seasons and climate conditions.Design Cohort study.Setting Fifteen regional centres across Japan.Participants A total of 100 304 children born from 2011 to 2014.Exposure Birth month, and mean sunshine duration (short/long) and humidity (high/low) in the first 6 months of life.Primary outcome measure Incidence of atopic dermatitis.Results The highest incidence of atopic dermatitis was in children born in the months of October to December. The lowest incidence of atopic dermatitis was in the months of April to June and in periods with a long duration of sunshine and high humidity. Low humidity was significantly associated with a higher incidence of atopic dermatitis. However, this significant difference disappeared when the birth season and parental history of allergic disease were considered in multivariate analysis.Conclusions In Japan, being born in the late autumn to early winter months is associated with a risk of developing atopic dermatitis until the age of 3 years. Sunshine duration and humidity from birth to 6 months of age are not associated with the incidence of atopic dermatitis.Data are available on reasonable request. Data are unsuitable for public deposition due to ethical restrictions and legal framework of Japan. It is prohibited by the Act on the Protection of Personal Information (Act No. 57 of 30 May 2003, amendment on 9 September 2015) to publicly deposit the data containing personal information. Ethical Guidelines for Medical and Health Research Involving Human Subjects enforced by the Japan Ministry of Education, Culture, Sports, Science and Technology and the Ministry of Health, Labour and Welfare also restricts the open sharing of the epidemiologic data. All inquiries about access to data should be sent to: jecs-en@nies.go.jp. The person responsible for handling enquiries sent to this email address is Dr Shoji F. Nakayama, JECS Programme Office, National Institute for Environmental Studies.