Table of Contents
Journal of Allergy
Volume 2011, Article ID 861926, 10 pages
Review Article

The Asthma-COPD Overlap Syndrome: A Common Clinical Problem in the Elderly

1Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of California, Davis, CA 95616, USA
2Genome and Biomedical Sciences Facility (GBSF), Center for Comparative Respiratory Biology and Medicine (CCRBM), Davis, CA 95616, USA
3VA Northern California Health Care System, Martinez, CA 94553, USA

Received 31 March 2011; Revised 30 July 2011; Accepted 31 July 2011

Academic Editor: Nicola Scichilone

Copyright © 2011 Amir A. Zeki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Many patients with breathlessness and chronic obstructive lung disease are diagnosed with either asthma, COPD, or—frequently—mixed disease. More commonly, patients with uncharacterized breathlessness are treated with therapies that target asthma and COPD rather than one of these diseases. This common practice represents the difficulty in distinguishing these disorders clinically, particularly in patients with a history that does not easily differentiate asthma from COPD. A common clinical scenario is an older former smoker with partially reversible or fixed airflow obstruction and evidence of atopy, demonstrating “overlap” features of asthma and COPD. We stress that asthma-COPD overlap syndrome becomes more prevalent with advancing age as patients respond less favorably to guideline-recommended drug therapy. We review the similarities and differences in clinical characteristics between these disorders, and their physiologic and inflammatory profiles within the context of the aging patient. We underscore the difficulties in differentiating asthma from COPD in current or former smokers, share our institutional experience with overlap syndrome, and highlight the need for new research to better characterize and investigate this important clinical phenotype.