The Role of Comorbidities in Difficult-to-Control Asthma in Adults and Children.

Assessment of asthma comorbidities, conditions that adversely affect the pathobiology of asthma or impair its response to therapies, is a fundamental step in the evaluation and management of patients with difficult-to-treat asthma. Identifying and effectively treating asthma comorbidities, such as obesity, obstructive sleep apnea, and chronic sinusitis with nasal polyps, may improve asthma control and reduce exacerbations. In addition, identifying comorbid T2 inflammatory conditions may help guide optimal selection of biologic therapies. Here, we describe common comorbid conditions found in adult and pediatric difficult-to-control asthma, discuss evidence for the association with asthma morbidity and treatment benefit, and provide information on how and when to assess comorbidities.