title: Asthma in preschool children: the next challenge.
abstract: OBJECTIVE
  To describe a prospective classification for preschool wheezers according to temporal symptom pattern, and summarize findings relating to the management of viral wheeze and the use of short-term therapy for intermittent severe wheeze.
  
  
  RESULTS
  Phenotypes defined from cohort studies should only be applied retrospectively at school age. A new classification that can be applied prospectively is discussed. The importance of early rhinovirus-induced wheezing as a risk factor for asthma has become apparent. However, there is no benefit from short-course oral steroids for acute viral wheeze in the majority of cases. There is conflicting evidence for the role of intermittent montelukast or inhaled steroids in the treatment of acute, intermittent wheeze. A link between reduced vitamin D intake during pregnancy and increased preschool wheeze in offspring has emerged, suggesting a potential role for vitamin D supplementation in primary prevention.
  
  
  CONCLUSIONS
  On the basis of current evidence, a trial of bronchodilators is first-line therapy for viral wheeze, and maintenance montelukast or inhaled steroids may be considered in preschool wheezers with persistent symptoms and risk factors for future asthma. No disease-modifying therapies are available. New therapeutic options for preschool wheezing disorders are desperately needed.
authors.affiliation: Department of Respiratory Paediatrics, National Heart & Lung Institute, Imperial College, London, UK.
authors.forename: Sejal
authors.initials: S
authors.lastname: Saglani
authors.forename: Andrew
authors.initials: A
authors.lastname: Bush
mesh_terms: D001249:Asthma / Q000175:diagnosis / Q000276:immunology* / Q000503:physiopathology / Q000517:prevention & control; D002675:Child, Preschool; D005260:Female; D006801:Humans; D010850:Picornaviridae Infections; D021041:Placental Circulation; D011247:Pregnancy; D019936:Probiotics; D012135:Respiratory Sounds; D012229:Rhinovirus / Q000276:immunology* / Q000472:pathogenicity; D012307:Risk Factors; D014807:Vitamin D
chemical_list: D014807:Vitamin D