Inflammatory comorbidity of upper and lower airways: epidemiology, mechanism and therapeutic Advances of Rhinitis Combined with Asthma.

Asthma and rhinitis are respectively the most common chronic inflammatory diseases of the lower airway and the upper airway. These two conditions often coexist as inflammatory disorders of the upper and lower airways. Clinical data generally show that the comorbidity of asthma patients with rhinitis or of patients with rhinitis having asthma significantly increases the disease burden of the patients. The core mechanism involves type 2 inflammatory pathways, neural reflex linkage, and systemic inflammatory dissemination. Currently, the treatment for the co-occurrence of rhinitis and asthma has shifted to an integrated approach. The combination of nasal and inhaled glucocorticoids serves as the basic treatment, while leukotriene receptor antagonists are the advantageous drugs for the comorbidity. Targeted biological agents such as anti- ‌immunoglobulin E and anti-interleukin-4 receptor α monoclonal antibodies achieve precise intervention on key pathways, while allergen immunotherapy offers the potential for etiological treatment. This review comprehensively elaborates on the epidemiological characteristics, pathophysiological mechanisms and treatment progress of this comorbidity, with the aim of providing a theoretical basis for future treatment of comorbidities.