Aims Currently, the asthma control is based on symptoms and lung function indices. The inflammatory markers like exhaled nitric oxide (FeNO) may provide additional data for asthma management. We aimed to correlate the FeNO levels with asthma exacerbations in children admitted to our pediatric department.

Methods 104 children (57 boys), aged 5 to 11, were enrolled to our 12 month survey. The monthly follow up visits comprised in clinical exam, childhood asthma control test (C-ACT), spirometry and FeNO measurement (NioxMino, Sweden). The analysis was done using the chi squared test.

Results 68 children experienced a total of 114 exacerbations during the survey. Only 23 exacerbations were associated with positive FeNO values (over 25 ppB), compared to 67 C-ACT positive: p=0.000; OR=0.17 (0.09–0.31); 44 spirometry positive: p=0.001; OR=0.40 (0.22–0.72) and 34 clinical positive findings: p=0.04; OR=0.59 (0.32–1.09). 21 of the positive FeNO cases (91%) had high values (over 50 ppB). On the other hand, 87 cases showed an increase in FeNO measurements without clinical exacerbation.

Conclusions Exhaled nitric oxide poorly correlates with asthma exacerbations, compared to “classical tools”. High values may be useful as a predictor, but the sensitivity and specificity are still uncertain.