Pneumoconiosis

Lung disease caused by mineral dust exposure

Aetiology

  • Assorted mineral dust
  • Heavy prolonged exposure to asbestos → asbestosis
  • 15-20 years coal dust exposure → coal workers pneumoconiosis
    • Caplan’s syndrome: caused by occupational dust inhalation in patients with RA
  • 15-20 years exposure to silica → silicosis

Pathophysiology

  • Inhaled particles which do not get cleared by the mucociliary clearance of the lungs become encased in macrophages and set off localised inflammatory responses
  • This leads to an inflammatory cascade that ultimately leads to fibroblast proliferation and collagen deposition

Clinical presentation

Simple pneumoconiosis

  • Usually asymptomatic - found incidentally on CXR
  • Can progress to the development of progressive massive fibrosis

Progressive massive fibrosis (complicated pneumoconiosis)

  • Dry cough
  • Progressive dyspnoea
  • Clubbing
  • Inspiratory crackles
  • NO PAIN - if asbestos exposure + pain think malignancy

Investigations

  • CXR
    • Simple pneumoconiosis - non-calcified multiple round opacities in the upper zone
    • Complicated pneumoconiosis - bilateral, upper-mid zone fibrotic masses, develops from periphery to hilum
  • High resolution CT often used to further quantify extent of disease
  • Spirometry - restrictive pattern

Management of progressive massive fibrosis

  • Bronchodilator, ICS
  • Oxygen if required
  • Pulmonary rehab