Incidence and remission of self-reported allergic rhinitis symptoms in adults

Background: A few studies have examined the incidence and remission of allergic rhinitis (AR) in the same general population. Methods: A questionnaire focused on respiratory symptoms and airway diseases was mailed out in 1992 and in 2000 to the same subjects. Of 4933 subjects, in 1992 aged 20-59 years, 4280 (86.8%) answered at both occasions. AR was defined on self-reported AR and a simultaneous report of nasal symptoms provoked by exposure either to tree-, grass-pollen, furred animals or house dust. Multiple logistic regression adjusted for age and gender was used to analyze potential predictors, reported in 1992, for incidence and remission of AR. Results: The prevalence of AR increased from 12.4% in 1992 to 15.0% in 2000. The incidence of AR from 1992 to 2000 was 4.8%, while 23.1% of the cases with AR in 1992 stated no AR symptoms in 2000 indicating remission. The highest incidence was seen in the youngest age group (20-29 years), whereas remission was highest in the oldest age group (50-59 years). Asthma symptoms during the last year (as reported in 1992) predicted increased incidence of AR and less chance for remission, 1.89 (95%CI 1.08-3.31) and 0.52 (0.31-0.87), respectively. Family histories of AR or asthma predicted increased incidence of AR 1.99 (1.42-2.80) and 1.62 (1.10-2.37), respectively, but were not associated with chance for remission, OR = 1.23 (0.81-1.87) and 0.94 (0.60-1.48). Conclusions: This study showed that AR became more common between 1992 and 2000, but also indicated remission in about 20% of the cases within the 8-year period, particularly in older ages. Asthma seems to be associated with higher risk for AR as well as less chance for remission, while heredity of asthma (or AR) may only be associated with the risk for the development and not remission of AR.