Constrictive Bronchiolitis

https://www.nejm.org/doi/full/10.1056/nejmoa1101388

Pathology

Membranous bronchioles develop mural smooth muscle hypertrophy or fibrous thickening with luminal narrowing.

Presentation

Patient factors

• Burn pit exposures / Iraq service
• inhalation exposure to: Nitrogen dioxide, sulfur dioxide, inorganic dust, fly ash, and diacetyl (popcorn)
• Post-transplant
• Rheumatologic conditions

Non-specific respiratory symptoms and exercise limitation

Workup

Imaging: shows air trapping on expiratory films in about 1/4. However, normal imaging findings occur in the majority due to the absence of alveolar disease

May have either obstruction or restriction on PFTs - though these are not required for the diagnosis

Diagnosed on lung biopsy