title: [Fifty percent of pollinosis patients sensitive to birch pollen demonstrate bronchoconstriction during bronchial provocation test with the allergen].
abstract: Birch pollens are known as seasonal asthma precipitants. Our earlier studies evidenced a very high frequency of positive results bronchial allergen challenges in pollinosis patients sensitive to grass pollen. The aim of the study was to evaluate how often the bronchial challenge with birch pollen allergen causes bronchoconstriction.
  
  
  METHODS
  Studies were performed outside of pollen season on 30 patients sensitive to birch pollen allergen. Before the allergen challenges bronchial provocation tests with methacholine were performed in all subjects.
  
  
  RESULTS
  About 13% of examined group had bronchial hyperreactivity (PC20FEV1Mch < 8 mg/ml) and 50% demonstrated bronchoconstriction after birch pollen allergen inhalation.
  
  
  CONCLUSIONS
  About 13 percent of patients sensitive to birch pollen demonstrated nonspecific hyperrectivity out of pollen season. Bronchial birch allergen challenge tests are positive in about half of birch sensitive patients with pollinosis.
authors.affiliation: Uniwersytet Medyczny w Białymstoku, Zakład Alergologii Dzieciecej.
authors.forename: Ewa
authors.initials: E
authors.lastname: Swiebocka
authors.forename: Zenon
authors.initials: Z
authors.lastname: Siergiejko
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Siergiejko
authors.forename: Adam
authors.initials: A
authors.lastname: Leoniuk
authors.forename: Jerzy
authors.initials: J
authors.lastname: Hofman
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D029662:Betula / Q000276:immunology*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D001985:Bronchial Provocation Tests; D016084:Bronchoconstriction / Q000276:immunology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011058:Pollen / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*
chemical_list: D000485:Allergens