A report published in April 2005 issue of Allergy showed that the exhaled levels of nitric oxide (NO) are closely related to asthma and allergy symptoms in children. As such, exhaled NO could represent a sensitive marker for allergy and asthma.
The study was done on 959 randomly selected school children between 13 and 14 years old from Sweden. Exhaled NO testing and spirometry were performed in all children and then correlated with questionnaire data.
The study results revealed that boys had significantly higher mean exhaled NO values than girls. Besides this the wheezing children had higher values than their non-wheezing peers. Similar associations were seen regarding hay fever and eczema symptoms.
On the other hand the investigators, found only weak associations between spirometry results and asthma. The researchers believed that the results indicate that measurements of exhaled NO is far superior to spirometry in identifying children with asthma especially allergic mild asthma.