408 Prevalence and Risk Factors Associated to Symptoms of Rhinoconjunctivitis in Mexican School Children. A Multicenter Study

BACKGROUND: According to ISAAC symptoms of allergic rhinoconjunctivitis (RC), have a worldwide prevalence of 8.5% in school children. Multiple risk factors had been associated with its prevalence, though little is known about the regional variations of these risk factors. OBJECTIVE: Identify the prevalence and the main risk factors associated to the presence of symptoms of rhinoconjunctivitis in the last 12 months in Mexican school children. METHODS: Cross-sectional, multicenter, prospective, based in ISAAC methodology of 9 registered sites in 8 cities (north, center and south of the Mexican Republic) with a validated and standardized survey applied to tutors of children aged 6 to 7 years old. Risk analysis was made through multivariate logistical regression, central tendency and dispersion measures were obtained with respective 95% confidence intervals. RESULTS: 24,902 surveys were obtained. The prevalence and 95%CI of symptoms of rhinitis was as follows: Monterrey 23%(21.4-24.5%), Mexicali 28.7% (26.9-30.5%), Ciudad Victoria 21.3%(19.7-22.8%), Villahermosa 39% (37-41%), North Federal District 45.6% (44.1-47.2%), Toluca-18.6% (17.3-20%), Tijuana 24.5% (22.9-26.1%), southeast Federal District 53%(50.7-55.4%) Veracruz 25% (23.1-26.8%) and conjunctivitis: Monterrey 8.8% (7.8-9.9%), Mexicali 13.2%(11.9-14.5%), Ciudad Victoria 7.3%(6.3-8.3%), Villahermosa 18.7% (17-20.3%), North Federal District 20.4%(19.1-21.7%), Toluca 7.3%(6.4-8.2%), Tijuana 8.7%(7.6-9.7%), southeast Federal District 25.1%(23-27.1%) Veracruz 8.7% (7.5-9.9%). The prevalence de rhinoconjunctivitis were 12.8%. Identified risk factors for the presence of rhinitis in the last 12 months were: asthma symptoms in the last 12 months OR-2.59 (95% CI, 2.25-2.98; P ≤ 0.0001), wheezing ever OR-1.78 (95% CI, 1.61-1.96; P ≤ 0.0001), eczema symptoms in the last 12 months OR-1.61 (95% CI, 1.35-1.93; P ≤ 0.0001), atopic dermatitis ever OR-2.97 (95% CI, 2.52-3.51; P ≤ 0.0001). Identified risk factors for the presence of conjunctivitis in the last 12 months were: wheezing ever OR-1.88 (95% CI, 1.64-2.16; P ≤ 0.0001), asthma symptoms in the last 12 months OR-2.97 (95% CI, 2.52-3.51; P ≤ 0.0001) eczema symptoms in the last 12 months OR-1.95 (95% CI, 1.58-2.41; P ≤ 0.0001), atopic dermatitis ever OR-2.14 (95% CI, 1.81-2.54; P ≤ 0.0001). CONCLUSIONS: The highest prevalence of rhinoconjunctivitis in Mexican School Children is in the southeast of the Federal District. The presence of asthma symptoms in the last 12 months, wheezing ever, eczema symptoms in the last 12 months, atopic dermatitis ever, risk factors are present symptoms of rhinoconjunctivitis.