Asthma, a prevalent chronic respiratory disease, manifests in heterogeneous phenotypes and endotypes, necessitating bespoke therapeutic approaches. Asthma exacerbations are characterized by worsening of symptoms and decline in lung function and present substantial challenges despite advances in understanding and treatment. Viral respiratory infections, notably those caused by rhinovirus, serve as primary triggers, with allergic sensitization and environmental exposures increasing susceptibility. Deficient antiviral responses in asthmatic airway epithelial cells, particularly impaired interferon production, perpetuate inflammation and hyperresponsiveness, contributing to exacerbations. Additionally, genetic polymorphisms influence host responses and susceptibility.
Recent studies underscore the association between specific inflammatory profiles, particularly eosinophil-mediated inflammation, and the frequency of exacerbations. Biologic therapies targeting inflammatory pathways show promise in reducing the frequency of exacerbations, thus underscoring the importance of understanding inflammatory phenotypes when selecting treatment. Notably, T2 inhibitors may modulate immune responses, potentially mitigating viral exacerbations.
Characterizing exacerbations is crucial for optimizing therapeutic strategies. Evidence suggests a dissociation between baseline inflammatory profiles and exacerbation phenotypes, highlighting the need for individualized management. Phenotyping exacerbations using sputum analysis helps to identify predominant inflammatory patterns and thus inform treatment decisions. The varied responses to biologic therapies further emphasize the importance of phenotyping exacerbations in refining treatment algorithms.
In conclusion, phenotyping asthma exacerbations provides valuable insights into underlying inflammatory mechanisms and enables personalized therapy. Understanding the complex interplay between viral triggers, inflammatory pathways, and responses to treatment is essential if we are to effectively manage severe asthma and reduce the burden of exacerbations. Further research into the mechanistic actions of biologic therapies in mitigating viral exacerbations is warranted to optimize asthma management strategies.

Key words: Severe asthma, Exacerbation, Phenotype, Biologic