Nasal polyps in patients with asthma: prevalence, impact, and management challenges.

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) often have coexisting asthma under the concept of "United Airway Disease", being the combination of both diseases, which is one of the most challenging phenotypes to treat. Although clinicians have recognized this difficult-to-treat phenotype for many years, it remained poorly characterized. There is increasing epidemiological evidence linking chronic rhinosinusitis and asthma, but a good understanding of the pathophysiology and the combined management is still lacking. Bronchial asthma is more prevalent in patients who suffer chronic rhinosinusitis, while asthmatic patients have a greater prevalence of CRSwNP than patients without asthma. The effect of CRSwNP treatment, whether medical or surgical, in asthma is today less controversial after some studies have shown improvement of asthma after medical and/or surgical treatment of CRSwNP. However, direct comparisons between surgical and medical treatments are limited. Further randomized clinical trials are, however, still needed to better understand the management when both asthma and CRSwNP occur together. This review aims at summarizing the prevalence, impact, and management challenges regarding both asthma and CRSwNP.