Rhinosinusitis as a Modifiable Determinant of Asthma Control in Children: A Narrative Review

Paediatric rhinosinusitis (RS), particularly chronic rhinosinusitis (CRS), is a common inflammatory condition with a significant impact on quality of life and a well-recognized association with asthma within the framework of united airway disease. This review aims to evaluate the impact of RS, mainly CRS, on asthma control in children and explore its role as a modifiable determinant. Mechanistically, RS and asthma share key pathophysiological features, including type 2 inflammation, epithelial barrier dysfunction, and airway microbiome dysbiosis, supporting the concept of a unified inflammatory process across the respiratory tract. Clinically, epidemiological data demonstrate a high prevalence of coexisting RS and asthma, with consistent associations with poorer asthma control, increased disease severity, and higher exacerbation burden, even in cases of subclinical sinonasal inflammation. Available observational evidence suggests that appropriate management of CRS, including medical therapy and, in selected cases, surgical intervention, may improve asthma outcomes such as symptom control and lung function. Targeted biologic therapies have shown clinical benefit in adolescents with CRS with nasal polyps (CRSwNP) and high type 2 inflammation, although paediatric data remain limited. However, the existing evidence is predominantly based on small, heterogeneous, observational studies. RS therefore represents a potentially treatable trait in paediatric asthma, warranting systematic evaluation in children with difficult-to-treat disease. Further prospective and interventional studies are needed to clarify causality and define the impact of RS on long-term outcomes.