Background The parent-of-origin effect is important in understanding the genetic basis of childhood allergic diseases and improving our ability to identify high-risk children. Objective We sought to ...investigate the parent-of-origin effect in childhood allergic diseases. Methods The Isle of Wight Birth Cohort (n = 1456) has been examined at 1, 2, 4, 10, and 18 years of age. Information on the prevalence of asthma, eczema, rhinitis, and environmental factors was obtained by using validated questionnaires. Skin prick tests were carried out at ages 4, 10, and 18 years, and total IgE measurement was carried out at 10 and 18 years. Parental history of allergic disease was assessed soon after the birth of the child, when maternal IgE levels were also measured. Prevalence ratios (PRs) and their 95% CIs were estimated, applying log-linear models adjusted for confounding variables. Results When stratified for sex of the child, maternal asthma was associated with asthma in girls (PR, 1.91; 95% CI, 1.34-2.72; P = .0003) but not in boys (PR, 1.29; 95% CI, 0.85-1.96; P = .23), whereas paternal asthma was associated with asthma in boys (PR, 1.99; 95% CI, 1.42-2.79; P < .0001) but not in girls (PR, 1.03; 95% CI, 0.59-1.80; P = .92). Maternal eczema increased the risk of eczema in girls (PR, 1.92; 95% CI, 1.37-2.68; P = .0001) only, whereas paternal eczema did the same for boys (PR, 2.07; 95% CI, 1.32-3.25; P = .002). Similar trends were observed when the effect of maternal and paternal allergic disease was assessed for childhood atopy and when maternal total IgE levels were related to total IgE levels in children at ages 10 and 18 years. Conclusions The current study indicates a sex-dependent association of parental allergic conditions with childhood allergies, with maternal allergy increasing the risk in girls and paternal allergy increasing the risk in boys. This has implications for childhood allergy prediction and prevention.
Background Rhinitis affects many young adults and often shows comorbidity with asthma. Objective We hypothesized that young adult rhinitis, like asthma, exhibits clinical heterogeneity identifiable ...by means of cluster analysis. Methods Participants in the Isle of Wight birth cohort (n = 1456) were assessed at 1, 2, 4, 10, and 18 years of age. Cluster analysis was performed on those with rhinitis at age 18 years (n = 468) by using 13 variables defining clinical characteristics. Results Four clusters were identified. Patients in cluster 1 (n = 128 27.4%; ie, moderate childhood-onset rhinitis) had high atopy and eczema prevalence and high total IgE levels but low asthma prevalence. They showed the best lung function at 18 years of age, with normal fraction of exhaled nitric oxide (F eno ), low bronchial hyperresponsiveness (BHR), and low bronchodilator reversibility (BDR) but high rhinitis symptoms and treatment. Patients in cluster 2 (n = 199 42.5%; ie, mild-adolescence-onset female rhinitis) had the lowest prevalence of comorbid atopy, asthma, and eczema. They had normal lung function and low BHR, BDR, F eno values, and total IgE levels plus low rhinitis symptoms, severity, and treatment. Patients in cluster 3 (n = 59 12.6%; ie, severe earliest-onset rhinitis with asthma) had the youngest rhinitis onset plus the highest comorbid asthma (of simultaneous onset) and atopy. They showed the most obstructed lung function with high BHR, BDR, and F eno values plus high rhinitis symptoms, severity, and treatment. Patient 4 in cluster 4 (n = 82 17.5%; ie, moderate childhood-onset male rhinitis with asthma) had high atopy, intermediate asthma, and low eczema. They had impaired lung function with high F eno values and total IgE levels but intermediate BHR and BDR. They had moderate rhinitis symptoms. Conclusion Clinically distinctive adolescent rhinitis clusters are apparent with varying sex and asthma associations plus differing rhinitis severity and treatment needs.
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