Preface During the mid 1900s, there was a growing interest for respiratory medicine in infants and children and, as such, diagnostic tools and techniques for assessment of lung function were developed. Paediatric pulmonology was further elaborated in Europe during the second part of the 20th century. The Paediatric Assembly within the European Respiratory Society (ERS) was established in 1993, 3 years after the Society was founded. Since then, the Paediatric Assembly has grown and is now the second largest Assembly within the ERS. There may be a number of factors which have influenced this increasing attention for paediatric pulmonology. The identification of specific disease entities such as cystic fibrosis, increasing incidence and prevalence of asthma, access to new and efficacious anti-asthma drugs, and the development of novel diagnostic techniques are all factors that are most likely to have contributed to the growing interest. Under these circumstances, it is a pleasure to announce the present issue of the European Respiratory Monograph, which is focused on respiratory diseases in infants and children. The Guest Editors have not attempted to cover the whole field, but rather to create an update of the important areas, as well as focusing on recent developments and future needs. As respiratory problems in childhood gradually transform into respiratory problems in adults, this Monograph is not addressed to paediatricians in particular. It concerns all who are interested in respiratory function and disorders. K. Larsson Editor in Chief Eur Respir Mon, 2006, 37, viii. Printed in UK - all rights reserved. Copyright ERS Journals Ltd 2006 European Respiratory Monograph ISSN 1025-448x. viii