INTERSTITIAL LUNG DISEASE: Edited Francesco Bonella and Steven D. NathanPitfalls in diagnosis and management of hypersensitivity pneumonitisWuyts, Wima; Sterclova, Marinab; Vasakova, MartinabAuthor Information aDepartment of Respiratory Medicine, Unit for Interstitial Lung Diseases, University Hospitals Leuven, Leuven, Belgium bDepartment of Respiratory Medicine of the 1st Medical School, Thomayer Hospital, Videnska, Prague, Czech Republic Correspondence to Wim Wuyts, Department of Respiratory Medicine, Unit for Interstitial Lung Diseases, University Hospitals Leuven, Belgium Herestraat 49, 3000 Leuven, Belgium. Tel: +32 16 34 68 02; e-mail: firstname.lastname@example.org Current Opinion in Pulmonary Medicine: September 2015 - Volume 21 - Issue 5 - p 490-498 doi: 10.1097/MCP.0000000000000199 Buy Metrics Abstract Purpose of review Hypersensitivity pneumonitis is a complex syndrome characterized by a combination of inflammation and fibrosis located in both the airways and the lung parenchyma. Both diagnosis and treatment are a real challenge for physicians. This review will focus on recent developments in this emerging field; furthermore, we will emphasize major gaps in the current knowledge, to stimulate further research in this field. Recent findings The main diagnostic issue is not to miss the entity as the clinical presentation is extremely variable even as the nature of the causal antigen. This article provides an overview of current ways to uncover possible causes of hypersensitivity pneumonitis. A problem of another kind is treatment of this disorder. Crucial in treatment is antigen avoidance, often in combination with immunosuppressive agents. The treatment of acute forms is rather straightforward, but the biggest endeavour, however, is treatment of chronic forms of hypersensitivity pneumonitis, which not always respond to immunosuppressive agents. Therefore, new initiatives should be taken in order to help clinicians in making a proper diagnosis and develop more efficacious treatment especially for patients suffering from chronic hypersensitivity pneumonitis. Summary Diagnosis and treatment of hypersensitivity pneumonitis remain a real challenge; this article provides an overview of our current understanding and points out new opportunities for further research. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.