MONTH OF BIRTH AND CHILDHOOD ATOPIC DISEASES IN THE TROPICS

The relationship between the month of birth and prevalence of diagnose d asthma, asthma-like symptoms (wheezing, nocturnal cough, and exercis e wheezing), rhinitis, and eczema was investigated in four cohorts eac h of primary schoolchildren and secondary school (high school) adolesc ents in Singapore by questionnaire survey. Significantly increased pre valence rates of diagnosed asthma and asthma-like symptoms were observ ed in certain birth months of the year for two adolescent cohorts, whi le significant association between birth month and presence of symptom s of rhinitis was found in a cohort of 6-7-year-olds. However, when de mographic factors were taken into consideration by multivariate analys is, only the association between asthma, asthma-like symptoms, and bir th month remained significant in one of the adolescent cohorts. There was, therefore, only a weak association between the month of birth and atopic disease in our schoolchildren. The overall seasonal trends, ho wever, did show two main seasons (March-May and September-November) as sociated with higher prevalence of these diseases.