Bronchiolitis Obliterans

Key points

• Bronchiolitis obliterans is a rare, progressive disease of the small airways causing irreversible airflow obstruction
• causes include lung or bone marrow transplantation, connective tissue disease, inhaled toxins, and post-infectious (especially in children)
• spirometry shows an obstructive pattern; chest X-ray is often normal, but HRCT typically shows mosaic attenuation with air trapping