The relationship between exhaled nitric oxide and allergic sensitization in a random sample of school children


J. G. C. van Amsterdam, Laboratory of Health Effects Research, National Institute of Public Health and the Environment, PO Box 1, 3720 BA Bilthoven, The Netherlands. E-mail:


Background Exhaled nitric oxide (NO) has been proposed as novel a non-invasive marker of airway inflammation.

Objective The level of exhaled NO was determined in a random sample of school children (7–12 years old) with the aim of investigating the relationship between exhaled NO and sensitization to common allergens.

Results In the 450 children tested by skin prick tests (SPT), the prevalence of sensitization was 29.5% (overall), 21.9% (sensitization to indoor allergens), and 15.0% (sensitization to outdoor allergens). Regression analysis showed that levels of exhaled nitric oxide were closely associated with various measures of sensitization to aeroallergens. Sensitization to indoor allergens was associated with higher levels of exhaled NO (eNO) than sensitization to outdoor allergens when assessed by IgE but not when assessed by SPT. Children with reported wheeze in the past 12 months had much stronger associations between sensitization and eNO than children without wheeze.

Conclusion We conclude that allergic sensitization is strongly associated with increased levels of exhaled NO, especially in children with wheeze.