Abstract
A spectrum of inflammatory and fibrotic disorders involving the small airways (i.e.,
respiratory and terminal bronchioles) may complicate connective tissue disorders (CTDs).
Obliterative (constrictive) bronchiolitis (OB) is a well-recognized, albeit rare,
complication of rheumatoid arthritis, and occasional cases have been described in
other CTDs. Bronchiolitis obliterans with organizing pneumonia (BOOP), also termed
cryptogenic organizing pneumonia, is a rare complication of CTDs. Clinical, radiographic,
histological features and prognosis differ markedly between these entities. Clinical
features are nonspecific, and the diagnosis (particularly OB) may be difficult. High
resolution thin section computed tomographic (HRCT) scans are useful in detecting
bronchiolar pathology, even when symptoms are minimal or absent. Surgical (open or
thoracoscopic) lung biopsies can substantiate the diagnosis, but in some cases, the
diagnosis can be affirmed less aggressively by appropriate imaging studies (e.g.,
HRCT) and transbronchial lung biopsies. Corticosteroids are highly efficacious for
BOOP, but therapeutic options for OB are disappointing.
Key Words:
airflow obstruction - bronchiolitis - obliterative bronchiolitis - constrictive bronchiolitis
- bronchiolitis obliterans organizing pneumonia - cryptogenic organizing pneumonia
- connective tissue diseases - rheumatoid arthritis
