Preface| Volume 56, ISSUE 1, Pxv-xvi, February 2023

The Unified Airway: From Concept to Practice

      While the close relationship between upper- and lower-airway disease has been known for centuries, the concept of the unified airway has come to the forefront in the last few decades. The April 2008 issue of Otolaryngologic Clinics of North America was dedicated to the unified airway and provided for the otolaryngologist a comprehensive review of the knowledge available at that time on this important concept. A common theme of the issue was the frequent co-occurrence of upper- and lower-airway disease and the need to recognize and treat these conditions concurrently. The concepts discussed highlighted the growing importance of multidisciplinary collaboration for the optimization of patient care.
      Nearly fifteen years later, advances in our understanding of airway inflammation have further refined the concept of the unified airway and have led to more targeted medical therapies. With a greater understanding of type 2 inflammation, we have seen the development and widespread use of biologics for the treatment of nasal polyps and asthma. We have also seen the impact of translational medicine on cystic fibrosis patients. The advent of CFTR modulators has transformed the way we manage the unified airway and has improved the quality of life and morbidity of these patients. With these new advances, close collaboration between otolaryngologists, allergists, pulmonologists, and other specialists has become critical for patient care.
      This issue of Otolaryngologic Clinics of North America provides an updated review of the pathophysiology underlying unified airway disease, specifically, the role of intrinsic factors, such as genetics/epigenetics, age (namely the pediatric population), and sex differences, and extrinsic factors, such as microbial infection and inhalants. Other sections are dedicated to the concept of classification and subtyping, which are now important aspects in the management of chronic rhinosinusitis and asthma. Two articles are dedicated to medical and surgical management of airway disease. Finally, several articles focus on specific conditions, such as autoimmune granulomatous disease, immunoglobulin deficiency, aspirin-exacerbated respiratory disease, and cystic fibrosis, all of which are conditions that highlight the centrality of the unified airway.
      While important themes are repeated throughout this issue, we believe that each set of expert authors presents their ideas from a unique perspective. A new issue dedicated to the unified airway is long overdue, and we hope that the articles can provide the otolaryngologist with a greater appreciation of important concepts as well as real, practical ways to advance everyday patient care.