46 Prevalence and Associated Risk Factors for Atopic Dermatitis Symptoms in Mexican Children

BACKGROUND: Describe AD prevalence and identify associated risk factors in Mexican children. METHODS: Multi-centric, cross-sectional ambiental survey. We applied the standardized Spanish-version ISAAC questionnaire to children's tutors aged 6 to 7 years in 8 Mexican cities. Sampling units randomly selected from local schools with advisable sample size of 3000 questionnaires per centre. Questions to evaluate actual AD: Has your child had itchy rash at any time in the past 12-months? Has this itchy rash at any time affected any of the following places: the folds of the elbows, behind the knees, in front of the ankles, under the buttocks or around the neck, ears or eyes? A risk analysis was made through multivariate logistical regression, central tendency and dispersion measures were obtained with respective 95% confidence intervals. RESULTS: A total of 25,809 questionnaires were applied at 274 schools. For current AD symptoms 18,095 questionnaires were analyzed and for severe current AD symptoms 19,173. Current AD symptoms mean global prevalence was 6.1% (95% CI, 5.7-6.4%). Mean prevalence and 95% CI per center: Monterrey 4.2% (3.5-4.9%), Mexicalli 6.3% (5.3-4.9%), Ciudad Victoria 2.3% (1.8-2.9%), Tijuana 4.9%(4.1-5.7%); North DF 8.5% (7.6-9.4%), Southeasat DF 9.4% (8.0-10.7%), Toluca 5.4% (4.6-6.2%); Veracruz 5.3% (4.3-6.2%); Villahermosa 8.6% (7.3-9.8%). Severe current AD symptoms mean global prevalence was 0.7% (95% CI, 0.6-0.9). Mean prevalence and 95% CI per center: Monterrey 0.6% (0.3-0.9%), Mexicalli 0.8% (0.5-1.2%), Ciudad Victoria 0.3% (0.1-0.6%), Tijuana 0.9% (0.5-1.2%); North DF 1.1% (0.7-1.5%), DF Southeast 1% (0.5-1.4%), Toluca 0.3% (0.1-0.5%); Veracruz 0.7% (0.4-1.1%); Villahermosa 1.2% (0.8-1.7%). Identified risk factors for current AD symptoms: presence of allergic rhinitis symptoms OR 1.94 (95% CI, 1.53-2.14; P ≤ 0.005); conjunctivitis symptoms OR 1.81 (95% CI, 1.53-2.14; P ≤ 0.005); accumulated asthma symptoms OR 1.51 (95% CI, 1.3-1.76; P ≤ 0.03). Identified risk factors for severe current AD symptoms: presence of conjunctivitis symptoms OR 2.20 (95% CI, 1.42-3.4; P ≤ 0.005); accumulated asthma symptoms OR 2.16 (95% CI, 1.38-3.39; P ≤ 0.005); use of acetaminophen in the first year of life OR 1.80 (95% CI, 1.21-2.69; P ≤ 0.005). CONCLUSIONS: Current AD symptoms prevalence was higher at north DF, followed by Toluca and southeast DF; current severe AD symptoms were higher at Villahermosa, followed by north DF and Tijuana. The presence of rhinoconjuntivitis and accumulated asthma symptoms doubles the risk for current AD and current severe symptoms in Mexican children and Acetaminophen use in the first year of life was associated with severe current AD symptoms.