Aim: To study the prevalence, characteristics of and risk factors for childhood rhinitis.
Methods: In a whole population birth cohort study (n = 1,456) the prevalence and characteristics of rhinitis among 10-y-old children were examined. At this age 1373 children (94%) completed standardized questionnaires, 1,043 (72%) skin-prick testing, 953 (65%) serum inhalant immunoglobulin E antibody screening and 784 (54%) methacholine bronchial challenges.
Results: At the age of 10 y the prevalence of hayfever ever was 18.6% and current nasal symptoms (rhinitis) 22.6%. Rhinitis at 10 y was largely seasonal and associated with low morbidity, although 62.7% of cases required pharmacological treatment. Atopy (positive skin test) and other allergic states were associated with rhinitis (p < 0.001). Wheeze or diagnosed asthma was higher with coexistent rhinitis. Among wheezing children physician-diagnosed asthma (p < 0.024) and inhaled corticosteroid use (p < 0.001) were greater with the presence of rhinitis. Significant bronchial hyperresponsiveness (methacholine concentration giving a 20% fall in forced expiratory volume in I s <4.0 mg ml(-1)) was greater if rhinitis was present even when the child did not wheeze (p < 0.001). Risk factor analysis for rhinitis identified the independent significance for atopy (p < 0.001) and eczema (p = 0.009) at the age of 4 y plus paternal rhinitis (p < 0.001), maternal rhinitis (p = 0.033) and maternal food allergy (p = 0.016).
Conclusion: Rhinitis is common at the age of 10 y, with strong associations with atopy, wheezing, asthma and bronchial hyperresponsiveness. An inherited predisposition towards atopy appears to predominate over environment in the aetiology of this state.