Abstract
Background: The incidence of allergic diseases has been rising
in the last decades. The interplay between genetic and environmental
factors underlined these complex diseases. Data concerning natural
history and risk factors associated with allergic diseases in developing
Asian countries are limited.
Methods: A population-based birth cohort study was conducted in
Bangkok, Thailand. Perinatal and postnatal factors were prospectively
collected by questionnaires. Sensitization was identified by skin prick
test. Food allergy (FA) was confirmed by oral food challenge.
Results: A total of 369 mother-children pairs were enrolled and
follow-up until the age of 30 months. The cumulative incidence of
allergic diseases was 46.2%. High family income significantly increased
risk of atopic dermatitis (AD) and ever-wheezing. Maternal history of
allergic diseases and exclusive breastfeeding longer than six months
significantly increased risk of FA. Antibiotics use in infants
significantly associated with FA, ever-wheezing and rhinitis. Infants
with FA had a 6.5-fold increased risk of AD while infants with AD had an
8.5-fold increased risk of FA. AR had a 3.5-fold increased risk
in developing ever-wheezing. One-third of the subjects had aeroallergen
sensitization.
Conclusion: Prevalence of allergic diseases in developing Asian
country was considerably high. AD and FA were the most prevalent
allergic diseases during the first years of life. Meanwhile, the
prevalence of wheezing and rhinitis subsequently increased over time.
High sensitization rate to aeroallergens was found in the first two
years of life. Maternal atopy, high family income, early life exposure
to antibiotics and prolonged breast-feeding increased risk of allergic
diseases in our cohort.
Keywords: natural history; risk factor; atopic dermatitis; food
hypersensitivity; asthma; rhinitis, allergic; Asia, Southeastern; cohort
studies
Impact statement: This is one of only few birth cohort
conducting in developing Asian countries. Our study contributes to
deeper insights in similarities and differences of natural history and
risk factors in early life allergic manifestations among different
population groups.