Infections in the nose and exacerbations of chronic respiratory disorders.

The respiratory tract is conventionally divided into the upper and lower airways. Although the two airways have distinct functions and are managed by different specialists, they also share many physiological and immunological characteristics. Problems of the nose and sinuses can impact on the lungs; conversely, lower respiratory tract disorders can affect the upper airways. This has given rise to the concept of “united airways disease”, and understanding the relationships between the mechanisms, epidemiology and treatment of upper and lower airways disorders is crucial as new therapeutic options become available. This ERS Monograph presents a comprehensive overview of the nose and sinuses in respiratory disorders, starting with chapters covering basic anatomy, histology and immunology, together with recent developments in imaging techniques and practical clinical examination. Other chapters focus on specific associations with cystic fibrosis (CF), infection and exacerbations, nasal polyposis and asthma, COPD, non-CF bronchiectasis and primary ciliary dyskinesia, and air pollution in chronic diseases. The “united airways” are further discussed in terms of the impact of optimal upper airways treatment on lower airways inflammation and current guidelines to aid all physicians, especially ENT specialists and chest physicians, in clinical practice.