Original Article|Articles in Press

Exhaled nitric oxide levels are associated with the severity of chronic epipharyngitis and decreased via epipharyngeal abrasion

Published:December 02, 2022DOI:



      The author previously demonstrated that the levels of oral exhaled nitric oxide (NO) were reduced by repeated epipharyngeal abrasive therapy (EAT) for chronic epipharyngitis along with the patients’ symptoms, suggesting that exhaled NO may be a useful outcome parameter of repeated EAT. This study aimed to investigate whether the levels of oral exhaled NO indicate the severity of epipharyngitis and whether an epipharyngeal abrasion immediately influences the amount of exhaled NO.


      Participants visited the author's clinic for the diagnosis and treatment of chronic epipharyngitis from November 2020 to March 2021. NO levels were measured orally before EAT, after nasal anesthesia and EAT without zinc chloride (ZnCl2), and after EAT with ZnCl2. The correlation between the endoscopic finding scores in conventional light and black spots and the cobblestone appearance with granular changes in band-limited light as well as the exhaled NO levels were determined.


      The study included 102 patients (30 males, 72 females; median age, 45.7 years). NO levels were significantly lower (p < 0.01) in EAT without ZnCl2 (17.0 [11.0–25.3]) and even lower with ZnCl2 (12.0 [8.0–21.0]) than before EAT (21.5 [15.8–35.0]). NO was significantly higher (p <0.01) in chronic epipharyngitis with the cobblestone appearance with granular changes (23.5 [17.0–37.8]) than without it (19.0 [15.0–23.5]). The total number of endoscopic finding scores and the exhaled NO levels showed a positive correlation (r = 0.251; p = 0.015). Additionally, the cobblestone appearance with granular changes and exhaled NO levels showed a positive correlation (r = 0.256; p = 0.013).


      EAT decreased immediately exhaled NO levels with or without ZnCl2, suggesting that physical stimulation with a cotton swab without ZnCl2 is therapeutic, and ZnCl2 may increase this effect. The endoscopic scores were significantly associated with the exhaled NO levels, suggesting that the exhaled NO levels represent the severity of epipharyngitis. The cobblestone appearance with granular changes, which indicates that pathologic ciliated epithelium, was significantly correlated and increased exhaled NO levels, suggesting that NO may be exhaled from ciliated epithelia. These results indicated that exhaled NO levels may be useful as an objective parameter to express the severity of epipharyngitis as well as the outcomes of repeated EAT.



      NO (nitric oxide), EAT (epipharyngeal abrasive therapy), ACE2 (angiotensin-converting enzyme 2), TMPRSS2 (transmembrane protease, serine 2), ZnCl2 (zinc chloride), NOS (nitric oxide synthase)
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