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 features

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