title: Fractional exhaled nitric oxide measurements are most closely associated with allergic sensitization in school-age children.
abstract: BACKGROUND
  Factors affecting fractional exhaled nitric oxide (FeNO) in early childhood are incompletely understood.
  
  
  OBJECTIVE
  To examine the relationships between FeNO and allergic sensitization, total IgE, atopic dermatitis, rhinitis, asthma, and lung function (spirometry) in children.
  
  
  METHODS
  Children at high risk of asthma and other allergic diseases because of parental history were enrolled at birth and followed prospectively. FeNO was measured by an online technique at ages 6 and 8 years. Relationships among FeNO, various atopic characteristics, and asthma were evaluated.
  
  
  RESULTS
  Reproducible FeNO measurements were obtained in 64% (135/210) of 6-year-old and 93% (180/194) of 8-year-old children. There was seasonal variability in FeNO. Children with aeroallergen sensitization at ages 6 and 8 years had increased levels of FeNO compared with those not sensitized (geometric mean; 6 years, 10.9 vs 6.7 parts per billion [ppb], P < .0001; 8 years, 14.6 vs 7.1 ppb, P < .0001). FeNO was higher in children with asthma than in those without asthma at 8 years but not 6 years of age (6 years, 9.2 vs 8.3 ppb, P = .48; 8 years, 11.5 vs 9.2 ppb, P = .03). At 8 years of age, this difference was no longer significant in a multivariate model that included aeroallergen sensitization (P = .33). There were no correlations between FeNO and spirometric indices at 6 or 8 years of age.
  
  
  CONCLUSIONS
  These findings underscore the importance of evaluating allergen sensitization status when FeNO is used as a potential biomarker in the diagnosis and/or monitoring of atopic diseases, particularly asthma.
authors.affiliation: Department of Pediatrics, University of Wisconsin-Madison, Madison, Wis, USA. djj@medicine.wisc.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Jackson
authors.forename: Christine M
authors.initials: CM
authors.lastname: Virnig
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Gangnon
authors.forename: Michael D
authors.initials: MD
authors.lastname: Evans
authors.forename: Kathy A
authors.initials: KA
authors.lastname: Roberg
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Anderson
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Burton
authors.forename: Lisa P
authors.initials: LP
authors.lastname: Salazar
authors.forename: Douglas F
authors.initials: DF
authors.lastname: DaSilva
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Shanovich
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Tisler
authors.forename: James E
authors.initials: JE
authors.lastname: Gern
authors.forename: Robert F
authors.initials: RF
authors.lastname: Lemanske
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000175:diagnosis* / Q000276:immunology; D045853:Exhalation / Q000276:immunology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis* / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D011446:Prospective Studies; D012220:Rhinitis / Q000175:diagnosis* / Q000276:immunology; D013147:Spirometry
chemical_list: D009569:Nitric Oxide; D007073:Immunoglobulin E