title: Following up infant bronchiolitis patients provided new evidence for and against the united airway disease hypothesis.
abstract: OBJECTIVE
  The united airway disease (UAD) hypothesis suggests that allergic rhinitis and asthma develop together. We evaluated the evidence for and against the UAD hypothesis at five to seven years of age after hospitalisation for bronchiolitis at less than six months.
  
  
  METHODS
  This study used prospective follow-up data for 102 children hospitalised for bronchiolitis under the age of six months. We included the presence of previous and current asthma, prolonged rhinitis and skin prick tests (SPT) to common inhaled allergens and lung function by impulse oscillometry (IOS) at five to seven years of age. Bronchial hyper-reactivity (BHR) was assessed using the exercise challenge test and bronchodilation test.
  
  
  RESULTS
  Current asthma, but not previous transient asthma, was associated with prolonged rhinitis and a positive SPT. BHR, which reflected reactive airways, but not lung function, was associated with respiratory allergy, namely the combination of current asthma, prolonged rhinitis and a positive SPT.
  
  
  CONCLUSIONS
  This post-bronchiolitis follow-up study suggested an association between respiratory allergy and reactive airways at five to seven years of age, which supported the UAD hypothesis. However, previous transient asthma and a reduction in lung function reduction did not support the hypothesis.
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland. eero.lauhkonen@fimnet.fi.
authors.forename: Eero
authors.initials: E
authors.lastname: Lauhkonen
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Petri
authors.initials: P
authors.lastname: Koponen
authors.affiliation: Seinäjoki Central Hospital, Seinäjoki, Finland.
authors.forename: Kirsi
authors.initials: K
authors.lastname: Nuolivirta
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Merja
authors.initials: M
authors.lastname: Helminen
authors.affiliation: Allergy Centre, Tampere University Hospital, Tampere, Finland.
authors.forename: Marita
authors.initials: M
authors.lastname: Paassilta
authors.affiliation: Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland.|Department of Clinical Physiology, Turku University Hospital, Turku, Finland.
authors.forename: Jyri
authors.initials: J
authors.lastname: Toikka
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Korppi
mesh_terms: D000403:Airway Resistance / Q000276:immunology* / Q000502:physiology; D000485:Allergens / Q000009:adverse effects / Q000276:immunology; D001249:Asthma / Q000209:etiology / Q000503:physiopathology; D001988:Bronchiolitis / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D012130:Respiratory Hypersensitivity / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D065631:Rhinitis, Allergic / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D012882:Skin Tests; D013147:Spirometry / Q000706:statistics & numerical data
chemical_list: D000485:Allergens
keywords: Allergic rhinitis; Asthma; Bronchiolitis; Pulmonary function; United airway disease