respiratory bronchiolitis associated interstitial lung disease; desquamative interstitial pneumonia (RBILD)

Etiology

idiopathic

Epidemiology

• smokers 40-60 years of age
• relatively rare

Pathology

• inflammation of respiratory bronchioles, alveolar ducts, & alveoli
• mild interstitial fibrosis
• pigmented alveolar macrophages within distal airways, airsacs & alveoli
• metaplasia of respiratory epithelium

Clinical manifestations

• cough
• dyspnea
• may be incidental finding in an otherwise asymptomatic active skoker

Diagnostic procedures

• pulmonary function testing:
  • obstructive or mixed obstructive-restrictive pattern
  • diminished DLCO

Radiology

• chest X-ray
  • diffusely prominent vascular/interstitial markings
  • 'dirty lungs'
• high resolution computed tomography (CT) of thorax
  • diffuse ground-glass opacities with little fibrosis
  • may show air-trapping or cysts
  • mid to upper lung centrilobular micronodules
  • may be normal

Management

• smoking cessation
• corticosteroids generally results in improvement
• prognosis is good

More general terms

• bronchiolitis
• interstitial pneumonia