title: Relationships among allergic rhinitis, asthma, and chronic rhinosinusitis.
abstract: BACKGROUND
  Chronic rhinosinusitis (CRS) is a common disease in the United States. There are a significant number of patients with CRS who are refractory to standard medical and surgical therapy. Many of these patients also have comorbid allergic rhinitis (AR) and asthma, although the underlying pathophysiology that connects these three conditions remains unclear.
  
  
  OBJECTIVE
  The goal of this article is to review the relationships among CRS, AR and asthma.
  
  
  METHODS
  Scientific literature that addresses the prevalence of AR and asthma in CRS populations, the effect of AR and asthma on CRS disease severity, and whether treatment of AR and asthma can affect CRS outcomes was reviewed.
  
  
  RESULTS
  The literature supports the relationship between AR and CRS, but there is no direct evidence of causality the between the two conditions. There is a high prevalence of CRS in patients with asthma and the presence of CRS is associated with worse asthma outcomes. There is weak evidence that treatment of CRS may improve asthma outcomes. Targeting type 2 inflammation via biologics is being investigated in the treatment of asthma and CRS.
  
  
  CONCLUSIONS
  AR, asthma, and CRS are closed related and understanding the associations among these comorbid diseases will have significant clinical implication.
authors: Department of Internal Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors: Mariel G
authors: MG
authors: Rosati
authors: Anju T
authors: AT
authors: Peters
mesh_terms: D001249:Asthma / Q000453:epidemiology*; D002908:Chronic Disease; D015897:Comorbidity; D018450:Disease Progression; D006801:Humans; D015995:Prevalence; D065631:Rhinitis, Allergic / Q000453:epidemiology*; D012852:Sinusitis / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology