title: Severe intermittent wheezing in preschool children: a distinct phenotype.
abstract: BACKGROUND
  Young children with wheezing predominantly with respiratory tract illnesses experience severe exacerbations separated by extended periods of wellness and may be described as having "severe intermittent wheezing," a diagnostic category not currently recognized in national guidelines.
  
  
  OBJECTIVE
  We sought to characterize a cohort of children with recurrent severe wheezing.
  
  
  METHODS
  A total of 238 children 12 to 59 months enrolled in the Acute Intervention Management Strategies trial were characterized through comprehensive allergy, asthma, environmental, and quality of life assessments.
  
  
  RESULTS
  Asthma symptoms over the period of the preceding year occurred at frequencies consistent with intermittent asthma, as 94.5% of children experienced activity limitation < or = 2 times per month. However, frequent severe exacerbations were common, because 71% experienced > or = 4 wheezing episodes over the period of the preceding year, 95% made at least 1 primary care visit, 52% missed school or daycare, 40% made an emergency department visit, and 8% were hospitalized for wheezing illnesses. Atopic features were common, including eczema (37%), aeroallergen sensitization (46.8%), and positive asthma predictive index (59.7%). Oral corticosteroid use in the previous year (59.7% of the cohort) identified a subgroup with more severe disease documented by a higher incidence of urgent care visits (P = .0048), hospitalizations (P = .0061), aeroallergen sensitization (P = .047), and positive asthma predictive indices (P = .007).
  
  
  CONCLUSIONS
  Among preschool children enrolled in the Acute Intervention Management Strategies trial, a subgroup was identified with severe intermittent wheezing characterized by atopic features and substantial illness-related symptom burden despite prolonged periods of wellness.
  
  
  CONCLUSIONS
  Preschool children with recurrent severe wheezing episodes experience significant illness-related morbidity and exhibit features of atopic predisposition.
authors.affiliation: Department of Pediatrics, Washington University, St Louis Children's Hospital, St. Louis, MOO 63110, USA. bacharier_L@kids.wustl.edu
authors.forename: Leonard B
authors.initials: LB
authors.lastname: Bacharier
authors.forename: Brenda R
authors.initials: BR
authors.lastname: Phillips
authors.forename: Gordon R
authors.initials: GR
authors.lastname: Bloomberg
authors.forename: Robert S
authors.initials: RS
authors.lastname: Zeiger
authors.forename: Ian M
authors.initials: IM
authors.lastname: Paul
authors.forename: Marzena
authors.initials: M
authors.lastname: Krawiec
authors.forename: Theresa
authors.initials: T
authors.lastname: Guilbert
authors.forename: Vernon M
authors.initials: VM
authors.lastname: Chinchilli
authors.forename: Robert C
authors.initials: RC
authors.lastname: Strunk
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology*; D002675:Child, Preschool; D015331:Cohort Studies; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D012008:Recurrence; D012135:Respiratory Sounds / Q000175:diagnosis* / Q000187:drug effects
chemical_list: D000305:Adrenal Cortex Hormones