Allergic and mixed rhinitis: Epidemiology and natural history.

Allergic rhinitis (AR) is a prevalent chronic respiratory problem in the United States associated with significant comorbidities and health care costs. Recent surveys suggest that mixed rhinitis (MR), which refers to patients with nonallergic AR (NAR) and AR, is a specific rhinitis subtype that may represent between 50 and 70% of all AR patients although the true prevalence of these conditions has not been confirmed. It is important to make a clear distinction between these chronic rhinitis (CR) phenotypes as symptom triggers; response to treatment and prevalence of comorbidities such as sinusitis may be significantly different. Incorporating patient centric questionnaires that can reliably characterize AR, MR, and NAR phenotypes will improve our ability to further investigate the natural history/epidemiology, mechanisms, and development of novel therapies for NAR-related CR subtypes.