Summary
Definition
History and exam
Key diagnostic factors
- exposure to avian protein antigen, especially excrement
- mold in work environment
- occupational exposure to chemicals
- dyspnea
- cough
Other diagnostic factors
- fever/chills
- malaise
- weight loss/anorexia
- bibasilar rales
- diffuse rales
- clubbing
Risk factors
- smoking
- viral infection
- exposure to avian protein antigen
- exposure to mold antigen
- exposure to bacterial antigen
- exposure to diisocyanate (e.g., epoxy resin)
- exposure to acid anhydride antigen (e.g., paint refinisher)
- exposure to metalworking fluid
- nitrofurantoin, methotrexate, roxithromycin, and rituximab
- herbal supplements with ayurvedic medicine
Diagnostic investigations
1st investigations to order
- Chest x-ray
- CT chest
- serum IgG
- pulmonary function test
- diffusing lung capacity of carbon monoxide
Investigations to consider
- bronchoalveolar lavage
- lung biopsy
Treatment algorithm
all patients
Contributors
Authors
Leslie Grammer, MD
Professor
Northwestern University Feinberg School of Medicine
Director
Ernest S. Bazley Asthma and Allergy Center
Clinic Practice Director
Allergy-Immunology
Northwestern Medical Faculty Foundation
Chicago
IL
Disclosures
LG declares that she has no competing interests.
Peer reviewers
Jordan Fink, MD
Professor of Pediatrics
Allergy-Immunology Division
Medical College of Wisconsin
Milwaukee
WI
Disclosures
JF is an author of a number of references cited in this topic.
Alec Chessman, MD
Professor of Family Medicine
Medical University of South Carolina
Charleston
SC
Disclosures
AC declares that he has no competing interests.
Toby M. Maher, MB, MSc, PhD, MRCP
Consultant Respiratory Physician
Interstitial Lung Disease Unit
Royal Brompton Hospital
London
UK
Disclosures
TMM has received consultancy fees from GSK, Actelion, and Philips Respironics. He has received lecture fees from Astra Zeneca and holds an unrestricted industry-academic grant from GSK.
Differentials
- Viral pneumonia
- Sarcoidosis
- Bronchiolitis obliterans
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