Exhaled Nitric Oxide in Airway Diseases of Children

The measurement of exhaled nitric oxide (ENO) is a simple and noninvasive approach for assessing airway inflammation. The purpose of this study was to investigate whether ENO levels were different in children with various types of airway diseases. We recruited 100 consecutive patients with different airway diseases and 42 healthy control subjects for the study. Allergic asthmatic patients with high specific immunoglobulin E (IgE) level to Dermatophagoides pteronyssinus (Derp) tended to have the highest specific ENO levels (48.28 ± 16.63 ppb; n = 24). Perennial allergic rhinitis patients with high specific IgE level to Der p had intermediate levels of ENO (20.81 ± 9.56 ppb; n = 40). Patients with interstitial pneumonia induced by Mycoplasma pneumoniae (9.44 ± 3.97 ppb; n = 12) or with simple upper respiratory tract infections (10.51 ± 4.19 ppb; n = 24) had ENO levels similar to those of the healthy control subjects (8.80 ± 3.03 ppb; n = 42). Increased ENO in asthmatic patients and perennial allergic rhinitis children with higher specific IgE level to Der p could be reduced significantly by inhaled and nasal budesonide. We concluded that ENO level may be a good indicator for the differentiation of patients with allergen-induced airway inflammatory diseases from those with infection-induced airway inflammatory diseases.