Clinical application of fractional exhaled nitric oxide and nasal nitric oxide levels for the assess eosinophilic inflammation of allergic rhinitis among children

Background: Allergic rhinitis is one of the most common nasal inflammatory diseases among children. Assessment of clinical symptoms, skin prick test and serum immunoglobulin E (IgE) are common methods used to diagnose allergic rhinitis and assess inflammation degree in clinical settings. However, via blood tests assess eosinophils inflammation is invasive, and may cause fear in children. It makes have burden of the diagnosis of allergic rhinitis. Nasal nitric oxide (nNO) and fractional exhaled nitric oxide (FeNO) are noninvasive, inexpensive, and can provide immediate results. These methods may therefore be preferable to assess the inflammation of allergic rhinitis. Methods: This study was a retrospective analysis. We recruited 61 children with allergic rhinitis from November 2019 to March 2020. The participants were assessed using the FeNO and nNO tests. We also administered questionnaires and carried out traditional allergen and blood tests. We analyzed the relationship between diagnosis results and FeNO and nNO levels before and after the treatment of allergic rhinitis, to investigate the clinical application of FeNO and nNO levels for assess eosinophilic inflammation of allergic rhinitis in children. Results: We observed a significant association both FeNO, nNO level with eosinophils, total IgE. In different levels of eosinophils (EOS), the correlation of detection parameters had obvious change. FeNO and nNO levels were obvious higher compared to pre-treatment. Conclusions: Using NO concentration can indicates the extent of allergic inflammation and can measure allergy treatment effects combine other influence indexes. The combined use of FeNO and nNO levels may be a useful method for assess the degree of eosinophilic inflammation of allergic rhinitis in children.