The role of upper airway pathology as a co-morbidity in severe asthma.

Severe asthma is a complex heterogeneous disease that is refractory to standard treatment and is complicated by multiple co-morbidities and risk factors. Several co-morbidities may contribute to worsen asthma control and complicate diagnostic and therapeutic management of severe asthmatic patients. Areas covered: A prevalent cluster of chronic upper airway co-morbid diseases is recognized in severe asthma. Evaluation for these disorders should always be considered in clinical practice. The aim of this review is to provide an updated overview of the prevalence, the pathogenetic mechanisms, the clinical impact and the therapeutic options for upper airway pathology in severe asthma, focusing on chronic rhinosinusitis and allergic rhinitis. Expert commentary: In the context of severe asthma, the clinical significance of upper airway co-morbidities is based on mutual interactions complicating diagnosis and management. A better analysis and understanding of phenotypes and endotypes of both upper and lower airway diseases are crucial to further develop targeted treatment.