Introduction: Exhaled nitric oxide (FeNO) is a putative non-invasive marker of eosinophilic airway inflammation with a good predictive value for allergic asthma in preschool children. The aim of the present study was to compare FeNO after acute viral bronchiolitis (AVB) in children aged less than 2 years without atopic dermatitis (AD) vs those with atopic dermatitis, as well as children with AD without any history of AVB.
Methods: Forty-two children (mean age +/- SD: 12.3 +/- 5.2 months; range 5.0-23.5; sex-ratio M: F=1.3: 1) were included in this prospective study, > 8 wks after an episode of AVB. The patients' atopic status was assessed both by clinical phenotype and IgE- mediated response to inhaled and/or food allergens. FeNO (ppb) was measured off-line by the chemoluminescence method on samples obtained from gas collected in a balloon during tidal breathing.
Results: There was a significant difference between the AVB/AD (23.4 +/- 14.3 ppb, n=15) vs the AVB without AD group (13.5 +/- 10. 1 ppb, n=13) or the AD without AVB group (11.0 +/- 8.3 ppb, n=14). Maternal feeding for more than 2 months decreased FeNO by 50%.
Conclusion: Atopic children below 2 years with AD produce more NO after AVB than non-atopic children or atopic children without any history of AVB. Maternal feeding decreases FeNO.