Bronchiolar complications of connective tissue disorders

A spectrum of inflammatory and fibrotic disorders involving the small airwa ys (i.e., respiratory and terminal bronchioles) may complicate connective t issue disorders (CTDs). Obliterative (constrictive) bronchiolitis (OB) is a well-recognized, albeit rare, complication of rheumatoid arthritis, and oc casional cases have been described in other CTDs. Bronchiolitis obliterans with organizing pneumonia (BOOP), also termed cryptogenic organizing pneumo nia, is a rare complication of CTDs. Clinical, radiographic, histological f eatures and prognosis differ markedly between these entities. Clinical feat ures 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 absen t. Surgical (open or thoracoscopic) lung biopsies can substantiate the diag nosis, but in some cases, the diagnosis can be affirmed less aggressively b y appropriate imaging studies (e.g., HRCT) and transbronchial lung biopsies . Corticosteroids are highly efficacious for BOOP, but therapeutic options for OB are disappointing.