Nasal Nitric Oxide in Children: A Review of Current Outreach in Pediatric Respiratory Medicine

Abstract

Nasal nitric oxide (nNO) is a gas synthesized by the inducible and constitutive NO synthase (NOS) enzyme in the airway cells of the nasal mucosa. Like lung nitric oxide, it is thought to be associated with airway inflammation in various respiratory diseases in children. The aim of our review was to investigate the current state of use of nNO measurement in children. A comprehensive search was conducted using the Web of Science and PubMed databases specifically targeting publications in the English language, with the following keywords: nasal NO, children, allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, primary ciliary dyskinesia (PCD), and cystic fibrosis (CF). We describe the use of nNO in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF based on the latest literature. nNO is a noninvasive, clinically applicable test for use in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF. It can be used as a complementary method in the diagnosis of these respiratory diseases and as a monitoring method for the treatment of allergic rhinitis and acute and chronic rhinosinusitis.

Current Challenges in Pediatric Asthma

“…Still, FeNO might be elevated in several conditions that are also a part of the multimorbidity of asthma: atopic dermatitis, food allergies, etc., and the extent of elevation does not reflect disease severity [ 37 , 38 ]. FeNO can be low in some conditions, although inflammation might be present, i.e., exposure to tobacco smoke [ 39 , 40 ]. Therefore, NO fraction is not a good enough biomarker to be taken as definite proof of asthma, and it also cannot be used rule out the possibility of its presence [ 41 ].…”