Worldwide time trends in prevalence of symptoms of rhinoconjunctivitis in children: Global Asthma Network Phase I.

BACKGROUND: The Global Asthma Network (GAN), by using the International Study of Asthma and Allergies in Childhood (ISAAC) methodology, has updated trends in prevalence of symptoms of childhood allergic diseases, including non-infective rhinitis and conjunctivitis ('rhinoconjunctivitis'), which is reported here. METHODS: Prevalence and severity of rhinoconjunctivitis were assessed by questionnaire among schoolchildren in GAN Phase I and ISAAC Phase I and III surveys 15-23 years apart. Absolute rates of change in prevalence were estimated for each centre and modelled by multi-level linear regression to compare trends by age group, time period and per capita national income. RESULTS: Twenty-seven GAN centres in 14 countries surveyed 74,361 13- to 14-year-olds ('adolescents') and 45,434 6- to 7-year-olds ('children'), with average response proportions of 90% and 79%, respectively. Many centres showed highly significant (p < .001) changes in prevalence of rhinoconjunctivitis in the past year ('current rhinoconjunctivitis') compared with ISAAC. The direction and magnitude of centre-level trends varied significantly (p < .001) both within and between countries. Overall, current rhinoconjunctivitis prevalence decreased slightly from ISAAC Phase III to GAN: -1.32% per 10 years, 95% CI [-2.93%, +0.30%] among adolescents; and -0.44% [-1.29%, +0.42%] among children. Together, these differed significantly (p < .001) from the upward trend within ISAAC. Among adolescents, centre-level trends in current rhinoconjunctivitis were highly correlated with those for eczema symptoms (rho = 0.72, p < .0001) but not with centre-level trends in asthma symptoms (rho = 0.15, p = .48). Among children, these correlations were positive but not significant. CONCLUSION: Symptoms of non-infective rhinoconjunctivitis among schoolchildren may no longer be on the increase globally, although trends vary substantially within and between countries.

The prevalence of atopic symptoms in children with otitis media with effusion.

OBJECTIVE: To determine the prevalence of allergic symptoms in children with otitis media with effusion (OME). STUDY DESIGN: A validated questionnaire from the International Study of Asthma and Allergies in Childhood was used to determine the prevalence of allergic symptoms in children. The questionnaire was completed by the parents of children with OME undergoing ventilation tube insertion, and the results were compared with a large reference group of school children of the same age. SUBJECTS AND METHODS: Children aged 6 or 7 years old with OME confirmed intraoperatively during ventilation tube insertion between 2001 and 2005 (n=89). The prevalence of allergic symptoms and nasal symptoms in children with OME was compared with an age-matched reference group. RESULTS: There was no difference in the prevalence of allergic symptoms suggesting rhinoconjunctivitis, asthma, or eczema between the OME and reference group. The prevalence of nasal symptoms, however, was greater in the children with OME than in the reference group 38.2 percent versus 23.5 percent (odds ratio=2.01; 95% confidence interval, 1.30-3.10; P<0.001). CONCLUSION: The prevalence of allergic symptoms was similar in 6- to 7-year-old children with OME and the reference group, suggesting a limited effect of allergy in the pathogenesis of OME in this age group. Nasal symptoms were more common in the OME group, which may reflect a higher prevalence of adenoidal hyperplasia.