Prevalence and predictors of rhinitis in Danish children and adolescents

Background: The prevalence of self‐reported symptoms of allergic rhinitis is increasing in many countries, but the reasons for this trend are not well understood. Data from a 6‐year follow‐up study of a population sample of children and adolescents (n=408), aged 7–17 years at enrolment in 1986, were analyzed to investigate the prevalence and predictors of self‐reported rhinitis. Methods: Case history was used to assess the presence or absence of rhinitis (sneezing and running or blocked nose not associated with a cold), asthma, and eczema. Pulmonary function, skin prick test reactivity, and airway responsiveness to histamine were measured in all participants; a screening test for IgE antibodies to common allergens (Magic Lite SQ, Allergy Screen, ALK, Denmark) was performed in 237 (58%) of the participants. Results: The point prevalence of rhinitis increased from the first to the second survey, 14% and 22%, respectively; 54 (13%) of the subjects reported rhinitis only at the second survey (new rhinitis). Confining the analysis to participants without symptoms of rhinitis at the first survey showed that self‐reported eczema (relative risk [RR] 2.3, 95% confidence interval [CI] 1.2–4.7), airway hyperresponsiveness (RR 2.5, CI 1.8–3.0), atopy to grass pollen (RR 2.6, CI 1.7–3.3), atopy to dog dander (RR 2.4, CI 1.6–3.3), and atopy to house‐dust mite (RR 2.7, CI 1.4–5.2) at the first survey predicted an increased risk of the presence of rhinitis at the second survey. A positive Allergy Screen test at enrollment was associated with an increased risk of self‐reported rhinitis at follow‐up (RR 2.4, CI 1.4–3.4). Conclusions: This longitudinal population study of children and adolescents showed an age‐related increase in the point prevalence of self‐reported rhinitis; furthermore, sensitization to common aeroallergens, airway hyperresponsiveness, and the presence of self‐reported eczema were significantly associated with an increased risk of subsequent development of rhinitis.