title: Environmental, inhaled and ingested causes of pulmonary fibrosis.
abstract: Pulmonary fibrosis is a general term that refers to a collection of connective tissue around alveolar structures. There are over 200 disorders where the lungs may be involved in a fibrotic response. To determine the cause of pulmonary fibrosis requires an in depth understanding of the pathogenesis of pulmonary fibrosis and breadth of knowledge of the causative agents and associated disorders that may lead to pulmonary fibrosis. A comprehensive evaluation of the patient is absolutely essential, starting with detailed history that includes an occupational and environmental history because fibrogenic exposures can occur in many settings. Equally important is a history of ingestion of pharmaceutical or nonpharmaceutical substances. A physical examination and judicious investigations are always a part of any comprehensive clinical assessment but they are not commonly helpful in elucidating the cause of most pulmonary fibrotic disorders. Although, a chest film is invariably done, a logical and strongly recommended next step is a high-resolution computed tomography (HRCT). HRCT provides a better assessment of the radiological pattern, may suggest a diagnosis as well as direct the site, and type of lung biopsy. If the history and investigations do not lead to a diagnosis then a lung biopsy is required. Prevention or removal of the inciting agent is critical to the treatment of these disorders and in some instances corticosteroids may be of help.
authors.affiliation: Department of Medicine, Respiratory Division, Vancouver General Hospital, V5Z 1M9, The University of British Columbia, Canada. nkhalil@interchange.ubc.ca
authors.forename: Nasreen
authors.initials: N
authors.lastname: Khalil
authors.forename: Andrew
authors.initials: A
authors.lastname: Churg
authors.forename: Nestor
authors.initials: N
authors.lastname: Muller
authors.forename: Robert
authors.initials: R
authors.lastname: O'Connor
mesh_terms: D000284:Administration, Oral; D000393:Air Pollutants / Q000009:adverse effects*; D000542:Alveolitis, Extrinsic Allergic / Q000139:chemically induced / Q000150:complications / Q000473:pathology; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects*; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D011009:Pneumoconiosis / Q000150:complications / Q000209:etiology / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000209:etiology / Q000473:pathology; D015262:Xenobiotics / Q000009:adverse effects*
chemical_list: D000393:Air Pollutants; D015262:Xenobiotics