A rural environment does not protect against asthma or other allergic diseases amongst Mexican children

Abstract

IntroductionThe commonly held notion that a rural environment decreases the frequency of allergic diseases has proven to be inconsistent amongst children. ObjectiveOur objective was to contrast the prevalence of bronchial asthma (BA), allergic rhinitis (AR), and atopic dermatitis (AD) between children that live in a rural environment and those that live in urban areas. MethodsWe carried out a cross-sectional study amongst children aged six to seven; they were selected through probabilistic, stratified and conglomerated sampling. The prevalence of BA, AR, and AD was identified with the use of the questionnaire provided by The International Study of Asthma and Allergies in Childhood, additionally, we inquired about each child's family history of atopy, their exposure to farm animals, the intake of unpasteurised cow's milk, and the number of siblings related to every child. We used logistic regression and multivariate analysis to determine the correlation between asthma, allergic diseases, and rural environment. ResultsWe included 189/1003 (18.8%) children from a rural environment, and 814/1003 (81.2%) from an urban area. BA and AR were associated to a family history of atopy (OR=2.15, p=0.001; OR=2.58, p=0.002, respectively). BA was more prevalent in males (OR=1.92, p=0.007). Notably, a higher number of siblings seems to protect against AR (OR=0.45, p=0.008). A paternal history of allergies was associated to AD. ConclusionsIn our study, we were unable to find protective factors in a rural environment that might decrease the prevalence of asthma or allergic diseases.