USA: New research has revealed that chronic rhinosinusitis (CRS) is associated with an increased risk of developing asthma and future exacerbations. The presence of coexisting allergic rhinitis (AR) identifies a higher-risk subgroup, emphasizing the need for phenotype-based management to reduce subsequent asthma burden.The findings, published in International Forum of Allergy & Rhinology, come from a large retrospective cohort study conducted by Austin J. Lee and Mohamad R. Chaaban. The study explored how CRS, with and without AR, influences the development of asthma using real-world data from a large US-based electronic health record database.CRS and AR are among the most common upper airway disorders, and their relationship with asthma has been widely recognized. However, less is known about how these conditions contribute to the onset of new asthma cases over time. To investigate this, researchers analyzed data from the TriNetX US Collaborative Network, which includes health records from over 100 million patients.The study included adults aged 18 years and above diagnosed with CRS between 2009 and 2019 and compared them with individuals without CRS. A separate analysis evaluated outcomes in patients with both CRS and AR versus those with CRS alone. The primary outcomes assessed were new-onset asthma and asthma exacerbations over 1-, 2-, and 5-year follow-up periods. The researchers reported the following findings:Chronic rhinosinusitis was associated with a significantly increased risk of developing asthma after adjusting for demographic and clinical factors.Within the first year, CRS patients had a 42% higher risk of new-onset asthma compared to controls.CRS was also linked to a greater risk of asthma exacerbations.The increased risk of asthma incidence and exacerbations persisted over longer follow-up periods.The presence of coexisting allergic rhinitis (AR) further amplified the risk.Patients with both CRS and AR had a substantially higher likelihood of developing asthma compared to those with CRS alone.The elevated risk remained consistent across all time points studied.Coexisting AR more than doubled the risk of asthma exacerbations.Similar trends were observed in patients with CRS with nasal polyps, supporting the consistency of findings across CRS subtypes.The study highlights the importance of recognizing AR as a key modifier of asthma risk in patients with CRS. While the research does not establish whether treating AR can directly reduce asthma risk, it strongly supports routine evaluation of AR in patients with CRS as part of comprehensive care.The authors note that these findings highlight the need for future prospective studies to determine whether targeted management of upper airway diseases can help reduce the downstream burden of asthma. Identifying high-risk patient groups based on disease phenotype may enable earlier interventions and improved long-term outcomes.Overall, the large-scale analysis provides important real-world evidence that CRS increases the likelihood of developing asthma, and that the presence of allergic rhinitis further amplifies this risk, pointing toward the need for more personalized approaches in airway disease management.Reference:Lee, A. J., & Chaaban, M. R. Allergic Rhinitis Amplifies Asthma Risk in Patients With Chronic Rhinosinusitis: A Large-Scale Retrospective Cohort Analysis. International Forum of Allergy & Rhinology. https://doi.org/10.1002/alr.70141