title: Office-based exhaled nitric oxide measurement in children 4 years of age and older.
abstract: BACKGROUND
  Fractional exhaled nitric oxide (FENO) is increasingly being used in the office-based management of asthma, but data in children are limited.
  
  
  OBJECTIVE
  To report FENO values in 4- to 7-year-old children with suspected asthma and characterize their relation to clinical variables and describe the relation among FENO levels, age, and sex in 4- to 18-year-old children with suspected asthma.
  
  
  METHODS
  Retrospective data in 4- to 18-year-old children (n = 825) who underwent FENO testing using the NIOX MINO device were collected and analyzed. Chart reviews were performed for the 4- to 7-year-old children (n = 75).
  
  
  RESULTS
  FENO values ranged from less than or equal to 5 to 89 ppb in 75 4- to 7-year-old children and less than or equal to 5 to 300 ppb in 750 > 7 to 18-year-old children. Approximately one tenth of 4- to 7-year-old children and one third of > 7 to 18-year-old children had FENO values indicative of eosinophilic/allergic inflammation (>35 ppb). In regression analysis of the 4- to 7-year-old children, increasing age (P = .03) and asthma severity (P = .01) were associated with higher FENO levels. Atopic dermatitis was significantly associated (P = .03), whereas allergic rhinitis was marginally associated (P = .06), with higher FENO levels. Inhaled corticosteroid use was associated with lower FENO levels (P = .02).
  
  
  CONCLUSIONS
  This study characterizes the largest cohort of 4- to 7-year-old children to undergo FENO testing in ambulatory asthma management. Correlations between FENO levels and clinical variables were consistent with established findings in older children. This preliminary real-world study suggests that FENO assessment may be feasible and useful in the office-based asthma management of children as young as 4 years.
authors.affiliation: Pediatric Residency Program, Children's Mercy Hospital, Kansas City, Missouri. Electronic address: cdinakar@cmh.edu.
authors.forename: Jill R
authors.initials: JR
authors.lastname: Hanson
authors.forename: Stephen A
authors.initials: SA
authors.lastname: De Lurgio
authors.forename: David D
authors.initials: DD
authors.lastname: Williams
authors.forename: Chitra
authors.initials: C
authors.lastname: Dinakar
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000453:epidemiology*; D004804:Eosinophils / Q000276:immunology; D045853:Exhalation; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D012189:Retrospective Studies
chemical_list: D000305:Adrenal Cortex Hormones; D009569:Nitric Oxide