Birth month and risk of atopic dermatitis: a nationwide population-based study.
An individual's birth month has been associated with allergic diseases, but little is known about the association between birth month and atopic dermatitis (AD).



The aim of this study was to investigate the risk of AD in children born in various months.



Using Taiwan's National Health Insurance Research Database, we conducted a case-control study that included 31 237 AD cases and 124 948 age- and gender-matched controls without AD. Data regarding sociodemographic factors and coexisting medical conditions were collected and controlled in the multivariate logistic regression to determine the adjusted odds ratios and 95% confidence intervals for AD associated with the participant's birth month.



Compared with people born in May, people born in December had the highest risk of AD (OR 1.17, 95% CI 1.10-1.25), followed by people born in October (OR 1.15, 95% CI 1.08-1.22) and November (OR 1.13, 95% CI 1.06-1.20). Low income (OR 1.28), asthma (OR 1.88), allergic rhinitis (OR 1.70), psoriasis (OR 2.36), vitiligo (OR 1.99), urticaria (OR 2.14), and systemic lupus erythematosus (OR 1.91) were significant coexisting medical conditions associated with AD.



Being born in December, October, or November may be associated with an increased risk of AD. Future investigations are needed to evaluate the possible mechanism behind the association between birth month and AD.
School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan.
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Kuo
Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan.|Health Policy Research Center, Taipei Medical University Hospital, Taipei, Taiwan.|Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Chen
School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan.|Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan.|Health Policy Research Center, Taipei Medical University Hospital, Taipei, Taiwan.|Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Liao
Department of Surgery, China Medical University Hospital, Taichung, Taiwan.|Department of Surgery, University of Illinois, Chicago, IL, USA.
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Yeh
Department of Dermatology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
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Chou
Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.|Department of Dermatology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
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Lee
School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan.|Department of Healthcare Administration, Asia University, Taichung, Taiwan.
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Lin
School of Chinese Medicine for Post-Baccalaureate, I-Shou University, Kaohsiung, Taiwan. hwathai@seed.net.tw.|Ph.D. Program for the Clinical Drug Discovery of Botanical Herbs, Taipei Medical University, Taipei, Taiwan. hwathai@seed.net.tw.
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Shih
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D036801:Parturition; D011159:Population Surveillance; D015995:Prevalence; D012621:Seasons; D012959:Socioeconomic Factors; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
atopic dermatitis; birth month