title: High prevalence of rhinitis symptoms without allergic sensitization in Estonia and Finland.
abstract: OBJECTIVE
  Allergic rhinitis and atopy are more common in urban than rural environments. Non-allergic rhinitis has not been studied to a great extent. We aimed to assess the relationship of rhinitis symptoms with different profiles of allergic sensitization, comparing this in rural and urban environments.
  
  
  METHODS
  The study population consisted of population-based cohorts of adults aged 26-60 from Helsinki, Finland, and rural Saaremaa and urban Tallinn, Estonia. We compared the results of a structured interview and skin prick tests and assessed the risk factors for rhinitis.
  
  
  RESULTS
  The prevalence of rhinitis symptoms with atopy was 32.7% in Helsinki, 20.8% in Tallinn, and 12.5% in Saaremaa (p<0.001). Rhinitis symptoms without atopy were found in 26.4%, 29.8%, and 29.3% (p=n.s.), respectively. In Helsinki, 87.3% of participants with atopy identified symptoms as allergic, compared to 57.0% in Tallinn and 47.5% in Saaremaa. Childhood in the countryside (OR 0.63), family history of allergic rhinitis (OR 1.89), and polysensitization (OR 15.99) were significantly associated with rhinitis symptoms with atopy in a multivariate logistic regression model. The most common sensitizers were pollens and animals in Helsinki and mites in Estonia. Exposure to environmental tobacco smoke (OR 1.50) and family history of allergic rhinitis (OR 1.70) were associated with rhinitis symptoms without atopy.
  
  
  CONCLUSIONS
  Rhinitis symptoms without allergic sensitization were common in both Finland and Estonia and were associated with environmental tobacco smoke. Family history of allergic rhinitis predisposed to rhinitis symptoms irrespective of atopy status.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Paula
authors.initials: P
authors.lastname: Pallasaho
authors.affiliation: HUCH Heart and Lung Center, Peijas Hospital, Helsinki, Finland ; University of Helsinki and Helsinki University Central Hospital, Vantaa, Finland.
authors.forename: Annette
authors.initials: A
authors.lastname: Kainu
authors.affiliation: Division of Clinical Physiology and Nuclear Medicine, Laboratory Department, Jorvi Hospital, Helsinki University Central Hospital, Espoo, Finland.
authors.forename: Maria
authors.initials: M
authors.lastname: Juusela
authors.affiliation: Department of Pulmonology, North Estonia Medical Centre Foundation, Tallinn, Estonia.
authors.forename: Mari
authors.initials: M
authors.lastname: Meren
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, HUCH Medical Imaging Center, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
authors.forename: Anssi
authors.initials: A
authors.lastname: Sovijärvi
keywords: allergic rhinitis; allergic sensitization; chronic rhinitis; nasal polyps