[Risk factors and prevalence of allergic rhinitis among Chilean children]

The prevalence of asthma and allergic rhinitis experienced a steady increase in the last years, probably associated to changes in lifestyles.

To assess the prevalence of allergic rhinitis, to evaluate changes over time (1994-2000), and to describe risk factors.

The International Study of Asthma and Allergies in Childhood (ISAAC) core questionnaire, with questions added about socioeconomic status (SES), was applied to 4594 children between 6-7 years old and 13-14 years old during october-december 2000. Attendance to public or private schools was also used a SES proxy. The results were compared with those of a similar survey in 5281 children, performed in 1994. Rhinitis symptoms (ever) (SR), rhinitis symptoms within last 12 months (SR12) and medical diagnosis of rhinitis (DR) were assessed.

There was a significant increase in the prevalence of SR, SR 12 and DR in both age groups in 2000, compared to 1994. SR older children showed a higher prevalence of SR compared with the youngest group (p=0.003). No age differences were observed in the prevalence of SR12 and DR. Both SR and SR12 were more prevalent at schools of medium and low-medium SES (p=0.003 and p=0.002 respectively). DR was significantly more prevalent among children of high SES. A better mother educational level was associated to higher prevalence of SR and SR12 (p=0.03 and p=0.04). Father educational level was associated to DR (p=0.007). The prevalence of SR12 was higher in households with carpets (p=0.017). The prevalence of DR was higher in houses with smokers (p=0.03) and gas heating (p=0.005). None of the three variables were related to gender.

The prevalence of SR, SR12 and DR increased significantly in a short time period (6 years). Our results support a positive association between DR and high SES.