Fractional Exhale Nitric Oxide in Children with Moderate Persistent Chronic Rhinitis

To evaluate fractional exhale nitric oxide (FeNo) in moderate to severe persistent chronic rhinitis Children age 5-15 years with moderate to severe chronic rhinitis were enrolled in a cross-sectional study. Skin prick test (SPT) to common aeroallergens, fractional exhaled nitric oxide (FeNO), and blood test for specific IgE (sIgE) to house dust mite (HDM) were performed. Fifty-four children were enrolled. The mean age of patients was 9.4 ± 2.4 years, 59.3% were male. SPT was positive in 47 children (87%): 32 children showed positive result to only HDM, 14 children were positive to HDM and other aeroallergens, 1 child had positive SPT to other aeroallergens. sIgE to HDM showed positive result in 45 children. Four children had the discordance result between sIgE and SPT to HDM. FeNo levels were significantly correlated with the level of sIgE and mean wheal diameter (MWD) to HDM (Pearson 0.433; P=0.001 and 0.535; P< 0.001). The level of FeNO in children with HDM sensitization (positive to sIgE and/or SPT) was significantly higher than those without HDM sensitization (28.7 ± 21.4 VS 7.8 ± 4.4 ppb; P <0.001). Children who had sIgE to HDM 0.35-50 KUA/L had significantly higher FeNO than those with sIgE to HDM >50.01 KUA/L (23.7 ± 19.1 VS 37.3 ± 22.8 ppb; P= 0.04). Moderate to severe persistent chronic rhinitis children with allergic sensitization have evidence of elevated fractional exhaled nitric oxide. This results would emphasize the significant of lower airways allergic inflammation in rhinitis children especially allergen those sensitization