Diffuse Panbronchiolitis

Epidemiology

  • Seen mainly in Asia (mostly in Japan), few case reports in North America and Europe
  • Not associated with smoking
  • Usually occurs in males >40 y/o
  • Associated With
    • Adult T-cell leukemia
    • Ulcerative Colitis

Etiology

  • Unknown

Physiology

  • Unclear
  • Normal ciliary function
  • Pseudomonas infection occurs late in disease course

Pathologic Pattern

  • Obliterative or proliferative BO may be seen
  • Peribronchiolar mononuclear infiltrate involving entire wall of respiratory bronchiole (lumen filled with acute inflammatory cells: neutrophils)
  • Intraalveolar foamy macrophages: within peribronchiolar alveolar septa
  • Proximal bronchiectasis:

Diagnosis

  • PFT’s: obstructive pattern
  • FOB: BAL reveals moderately increased WBC with neutrophilic predominance
    • Intraluminal acute inflammatory exudate usually represent superimposed bacterial infection
  • CXR/Chest CT Patterns
    • Interstitial small nodular infiltrates (lower zone predominance) with hyperinflation:
  • HRCT: panbronciolitis/ bronchiectasis/ small linear branching opacities/ small nodules in centrilobular areas
  • Ig levels: normal

Clinical

  • Rapidly Progressive Airway Obstruction (see [[Obstructive Lung Disease]])
    • Dyspnea
  • Chronic Sinusitis: typical

Treatment

  • Low-Dose Erythromycin
    • Dose: 200 mg PO qday
    • Marked improvement in symptoms and CXR (unclear mechanism)
  • Steroids/Immunosuppressives: no role in this disease

References

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