CHEST Experts Issue Advice for Investigating Occupational and Environmental Causes of Chronic Cough

Expert panel warns of gap between current guidelines and clinical practice, reports CHEST

Glenview, IL, 3 November, 2016

Although the understanding of cough triggered by occupational and environmental causes has improved, experts say there is still a gap between current guidelines and clinical practice. A report by the CHEST Expert Cough Panel published in the journal CHEST suggests an approach to investigating occupational and environmental causes when these are suspected. The report has been endorsed by professional associations in the U.S., Canada, and Asia.

Coughing is one of the most common reasons people visit a family doctor. Chronic cough can be triggered when a person is exposed to certain irritants in the air and can be of little consequence, or it can be a symptom of more significant disease.  

The American College of Chest Physicians (CHEST) first published evidence-based guidelines on the diagnosis and management of cough in 1998 and updated these guidelines in 2006. Since the previous statement, there has been an increased understanding of the mechanisms of cough related to environmental triggers. There have also been several studies that have clarified laryngeal disorders leading to chronic cough and the role of occupational and environmental triggers for laryngeal causes of cough.

For the purpose of this latest report, experts reviewed occupational and environmental contributions to chronic cough with a focus on factors not covered in the 2006 Cough Guideline. They provided suggestions for investigating and managing these factors when suspected.

“We recently identified ten general chronic cough guidelines and protocols, but only the three published since 2006 included advice on detailed occupational and environmental assessments. One additional cough statement focused entirely on occupational cough,” explained lead investigator Susan M. Tarlo, MBBS, FCCP, of Toronto Western Hospital, and University of Toronto, Ontario, Canada. “However, of the 28 cohort studies of patients with chronic cough that specifically noted that they followed guidelines or protocols, none provided details regarding occupational and environmental assessments, suggesting a gap between recommended guidelines and clinical practice.”

The CHEST Expert Cough Panel performed a comprehensive literature search using the MEDLINE and TOXLINE literature databases, supplemented by articles identified by the panel’s occupational and environmental subgroup members, to identify occupational and environmental contributions to chronic cough. The literature review identified relevant articles regarding mechanisms, allergic environmental causes, chronic cough and the recreational and involuntary inhalation of tobacco and marijuana smoke, nonallergic environmental triggers, laryngeal syndromes and occupational diseases and exposures.

The subgroup developed guideline recommendations or suggestions, which then underwent review and voting by the full cough panel. Consensus-based statements were developed for the approach to diagnosis due to a lack of strong evidence from published literature.

The panel makes four main recommendations for examining adult patients with chronic cough:

  • Occupational and environmental causes should be routinely elicited in the history, including length, severity, and timing of the exposure in relation to the onset or worsening of the patient’s cough, smoking history and atopic history, reviewing Material Safety Data Sheets and/or occupational hygiene reviews of the patient’s workplace, and the time period between last exposure and medical evaluation
  • Where the history suggests an occupational or environmental cause, the panel suggests lung function testing and when appropriate rhinolaryngoscopy (a method for examining the nose and throat)
  • Where there is a history of occupational or environmental exposure, the panel suggests a number of objective tests such as sputum cytology, before and after exposure methacholine tests to demonstrate potential causality, immunologic tests, and tests for chronic beryllium disease
  • Where there is a high suspicion that cough is due to environmental and/or occupational exposures, the panel suggests that these patients be managed according to evidence-based guidelines for these exposures and/or be referred to specialists with expertise in environmental and occupational disease

“There is a need for further documentation of occupational and environmental causes of cough and to close the gap between guidelines and clinical practice,” commented Tarlo. “Identifying occupational and environmental causes of chronic cough can affect symptom management and offers opportunity for exposure control and prevention in the future.”

This report has been endorsed by the American College of Allergy, Asthma, and Immunology, the American Association for Respiratory Care, the Asian Pacific Society of Respirology, the Canadian Thoracic Society, and the Occupational and Environmental Medicine Association of Canada.

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Notes for editors
The article is "Occupational and Environmental Contributions to Chronic Cough in Adults: CHEST Expert Panel Report," by Susan M. Tarlo, MBBS, FCCP, Kenneth W. Altman MD, PhD, John Oppenheimer, MD, Kaiser Lim, MD, Anne Vertigan, PhD, MBA, BAppSc (Sp Path), David Prezant, MD, and Richard S. Irwin, MD, Master FCCP, on behalf of the CHEST Expert Cough Panel (doi:10.1016/j.chest.2016.07.029). It appears in CHEST, volume 150, issue 4 (2016), published by Elsevier.

Copies of this paper and interviews with the authors are available to credentialed journalists upon request; please contact Andrea Rodriguez, American College of Chest Physicians at +1 312-833-7947 or andrea.j.rodriguez@gmail.com.

About CHEST
CHEST, the official publication of the American College of Chest Physicians, features the best in peer-reviewed, cutting-edge original research in the multidisciplinary specialties of chest medicine: pulmonary, critical care and sleep medicine; thoracic surgery; cardiorespiratory interactions; and related disciplines. Published since 1935, it is home to the highly regarded clinical practice guidelines and consensus statements. Readers find the latest research posted in the Online First section each week and access series that provide insight into relevant clinical areas, such as Recent Advances in Chest Medicine; Topics in Practice Management; Pulmonary, Critical Care and Sleep Pearls; Ultrasound Corner; Chest Imaging and Pathology for Clinicians; and Contemporary Reviews. Point/Counterpoint Editorials and the CHEST Podcasts address controversial issues, fostering discussion among physicians. www.chestnet.org/Publications/CHEST-Publications/CHEST-Journal

About the American College of Chest Physicians (CHEST)
CHEST is the global leader in advancing best patient outcomes through innovative chest medicine education, clinical research and team-based care. Its mission is to champion the prevention, diagnosis and treatment of chest diseases through education, communication and research. CHEST serves as an essential connection to clinical knowledge and resources for its 19,000 members from around the world who provide patient care in pulmonary, critical care and sleep medicine. For more information, visit chestnet.org.

About Elsevier
Elsevier is a world-leading provider of information solutions that enhance the performance of science, health, and technology professionals, empowering them to make better decisions, deliver better care, and sometimes make groundbreaking discoveries that advance the boundaries of knowledge and human progress. Elsevier provides web-based, digital solutions — among them ScienceDirect, Scopus, Research Intelligence and ClinicalKey— and publishes over 2,500 journals, including The Lancet and Cell, and more than 35,000 book titles, including a number of iconic reference works. Elsevier is part of RELX Group, a world-leading provider of information and analytics for professional and business customers across industries. www.elsevier.com

Media contact
Andrea Rodriguez
American College of Chest Physicians (CHEST)
+1 312 833 7947
andrea.j.rodriguez@gmail.com