title: Degree and clinical relevance of sensitization to common allergens among adults: a population study in Helsinki, Finland.
abstract: BACKGROUND
  We aimed to assess the prevalence of allergic sensitization and multiple sensitization, risk factors, and the clinical impact of being sensitized in the adult population of Helsinki, Finland.
  
  
  METHODS
  As a part of the FinEsS study, a population-based random sample of 498 adults aged 26-60 years were tested for 15 common aeroallergens with skin prick tests (SPTs) and interviewed on respiratory symptoms and diseases, including respiratory irritants and childhood environment.
  
  
  RESULTS
  The prevalence of at least one positive prick test was 46.9%. A large difference by age was found: 56.8% were sensitized among those aged 26-39 years, 49.2% in the age group 40-49 years, and 35.6% in the age group 50-60 years (P<0.001). Sensitization to multiple allergens was common among young subjects with 42% of the sensitized responding to at least four allergens, while this proportion was only 16% of the sensitized among those aged 50-60 years. The prevalence of physician-diagnosed asthma, allergic rhinitis (AR) or conjunctivitis, and wheeze increased significantly with increasing number of positive responses to SPTs. Having a family history of AR or conjunctivitis was a significant risk factor for allergic sensitization and for sensitization to any of the pollens. Further, urban living in childhood yielded an increased risk for pollen sensitization.
  
  
  CONCLUSIONS
  The prevalence of allergic sensitization was high in the urban adult population of Helsinki. More than half of those aged 26-39 years was sensitized and 24% was sensitized to at least four allergens. Sensitization to multiple allergens was associated with a high prevalence of asthma, AR or conjunctivitis, and wheeze.
authors.affiliation: Skin and Allergy Hospital, Helsinki University Central Hospital, Helsinki, Finland. paula.pallasaho@fimnet.fi
authors.forename: P
authors.initials: P
authors.lastname: Pallasaho
authors.forename: E
authors.initials: E
authors.lastname: Rönmark
authors.forename: T
authors.initials: T
authors.lastname: Haahtela
authors.forename: A R A
authors.initials: AR
authors.lastname: Sovijärvi
authors.forename: B
authors.initials: B
authors.lastname: Lundbäck
mesh_terms: D000328:Adult; D017677:Age Distribution; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000453:epidemiology / Q000276:immunology; D003231:Conjunctivitis / Q000453:epidemiology / Q000276:immunology; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D015995:Prevalence; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology / Q000276:immunology; D012307:Risk Factors; D012882:Skin Tests; D014504:Urban Health
chemical_list: D000485:Allergens