title: Pollen immunotherapy reduces the development of asthma in children with seasonal rhinoconjunctivitis (the PAT-study).
abstract: BACKGROUND
  Children with allergic rhinitis are likely to develop asthma.
  
  
  OBJECTIVE
  The purpose of this investigation was to determine whether specific immunotherapy can prevent the development of asthma and reduce bronchial hyperresponsiveness in children with seasonal allergic rhinoconjunctivitis.
  
  
  METHODS
  From 6 pediatric allergy centers, 205 children aged 6 to 14 years (mean age, 10.7 years) with grass and/or birch pollen allergy but without any other clinically important allergy were randomized either to receive specific immunotherapy for 3 years or to an open control group. All subjects had moderate to severe hay fever symptoms, but at inclusion none reported asthma with need of daily treatment. Symptomatic treatment was limited to loratadine, levocabastine, sodium cromoglycate, and nasal budesonide. Asthma was evaluated clinically and by peak flow. Methacholine bronchial provocation tests were carried out during the season(s) and during the winter.
  
  
  RESULTS
  Before the start of immunotherapy, 20% of the children had mild asthma symptoms during the pollen season(s). Among those without asthma, the actively treated children had significantly fewer asthma symptoms after 3 years as evaluated by clinical diagnosis (odds ratio, 2.52; P <.05). Methacholine bronchial provocation test results improved significant in the active group (P <.05).
  
  
  CONCLUSIONS
  Immunotherapy can reduce the development of asthma in children with seasonal rhinoconjunctivitis.
authors.affiliation: Department of Paediatrics, Umeå University, Sweden.
authors.forename: Christian
authors.initials: C
authors.lastname: Möller
authors.forename: Sten
authors.initials: S
authors.lastname: Dreborg
authors.forename: Hosne A
authors.initials: HA
authors.lastname: Ferdousi
authors.forename: Susanne
authors.initials: S
authors.lastname: Halken
authors.forename: Arne
authors.initials: A
authors.lastname: Høst
authors.forename: Lars
authors.initials: L
authors.lastname: Jacobsen
authors.forename: Antti
authors.initials: A
authors.lastname: Koivikko
authors.forename: Dieter Y
authors.initials: DY
authors.lastname: Koller
authors.forename: Bodo
authors.initials: B
authors.lastname: Niggemann
authors.forename: Lene A
authors.initials: LA
authors.lastname: Norberg
authors.forename: Radvan
authors.initials: R
authors.lastname: Urbanek
authors.forename: Erkka
authors.initials: E
authors.lastname: Valovirta
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wahn
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis / Q000517:prevention & control*; D029662:Betula / Q000009:adverse effects / Q000276:immunology; D001985:Bronchial Provocation Tests; D002648:Child; D003233:Conjunctivitis, Allergic / Q000209:etiology / Q000628:therapy*; D003888:Desensitization, Immunologic; D006801:Humans; D016210:Methacholine Chloride / Q000494:pharmacology; D006109:Poaceae / Q000009:adverse effects / Q000276:immunology; D011058:Pollen / Q000009:adverse effects / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000209:etiology / Q000628:therapy*; D012621:Seasons
chemical_list: D016210:Methacholine Chloride