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SynopsisBronchiolitis obliterans is a condition marked by diffuse lung damage that can affect both infants and adults and immunocompetent and immunocompromised patients. It is characterized by injury to the small airways (bronchioles) resulting in progressive narrowing of bronchial lumens. Causes include inhalation injury (eg, chlorine, ammonia, diacetyl), infection (eg, adenovirus, influenza, parainfluenza, respiratory syncytial virus), medications (eg, rituximab, sulfasalazine), toxic fumes (eg, silos, welders, military), and graft-versus-host disease following bone marrow or rejection following lung transplantation. Bronchiolitis obliterans may also been seen in the setting of autoimmune diseases like rheumatoid arthritis.
Diacetyl is a flavoring compound often used in e-cigarettes / vape pens. Its former use in factories manufacturing microwave popcorn was associated with diagnoses of bronchiolitis obliterans, thus sometimes known as "popcorn lung."
The clinical syndrome manifests as an airway obstruction, cough, and slowly progressive dyspnea (weeks to months), with radiographic examination showing normal or hyperinflation of the lungs. Tachypnea, crackles, and/or wheezing may be evident on physical examination.
Related topic: Bronchiolitis
J42 – Unspecified chronic bronchitis
40100001 – Obliterative bronchiolitis
Differential Diagnosis & Pitfalls
- Chronic obstructive pulmonary disease (COPD)
- Follicular bronchiolitis
- Interstitial fibrosis
- Hypereosinophilic obliterative bronchiolitis
Drug Reaction DataBelow is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.