Dust mite-dominant sensitization pattern as a causal factor for adult-onset asthma

Dear Editor, Atopy or allergic sensitization is an important causative factor for asthma, particularly in younger age groups; however, attribution varies with age, with allergy being more strongly related to asthma in children compared to adults. The causal effect of atopy on adult-onset asthma is not certain, especially because allergic sensitization in asthma may be an inconstant secondary effect of asthma instead of its cause. We previously used a Mendelian randomization strategy to examine whether atopy is a cause of adult asthma or a consequence of it, and reported that the estimated proportion of adult patients with atopic asthma attributable to genetic susceptibility to atopy was 16.6%.