Background: The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire allows users to fi nd factors associated with allergic diseases, but thus far most of the studies on risk factors for allergic diseases have been devoted to asthma and not to rhinitis.

Objective: To determine the main factors associated with symptoms of allergic rhinitis and rhinoconjunctivitis in school children and adolescents in northern Mexico City.

Patients and Methods: A cross sectional, multicenter survey was conducted in northern Mexico City, in children aged 6-7 and 13-14 years. The survey instrument was the Phase Three B ISAAC questionnaire, which was validated and standardized in Spanish.

Results: There were 4106 6-7-year-olds and 6576 13-14-year-olds. The total prevalence of diagnosis of allergic rhinitis was 4.6%. The prevalence of cumulative and current symptoms of rhinitis was considered high (>29%), but the prevalence of the diagnosis of allergic rhinitis was considered low (ranging from 3.4% to 5.6%). The prevalence of symptoms of rhinitis with conjunctivitis had intermediate values (ranging from 20.3% to 30.2%). Cumulative symptoms of allergic rhinitis, current symptoms of allergic rhinitis, and rhinoconjunctivitis were related to symptoms of current or cumulative asthma, symptoms of current or cumulative atopic eczema, and current use of paracetamol
(odds ratio > 1, P < .05).

Conclusion: The present results support the concept of rhinitis and asthma as common chronic respiratory diseases, and this study also found a relation between paracetamol use and rhinitis in children.

Key words: Rhinitis. Asthma. ISAAC. Survey. Paracetamol. Mexico.