pneumoconiosis

Question 1

definition

Answer 1

Fibrosing interstitial lung disease caused by chronic inhalation of mineral dusts.
- Simple: Coalworker’s pneumoconiosis or silicosis (symptom-free).
- Complicated: Pneumoconiosis (progressive massive fibrosis) results in loss of lung function.
- Asbestosis: A pneumoconiosis in which diffuse parenchymal lung fibrosis occurs as a result
of prolonged exposure to asbestos.

Question 2

aetiology

Answer 2

Caused by inhalation of particles of coal dust, silica or asbestos (two main types of fibre: white asbestos and blue asbestos or crocidolite, the latter is more toxic).

Question 3

history/symptoms

Answer 3

Occupational history is important, there may be a long latency between disease exposure and expression.

Asymptomatic: Picked up on routine CXR (simple coal or silica pneumoconiosis).

Symptomatic: There is usually insidious onset of shortness of breath and a dry cough. Occasionally, black sputum (melanoptysis) is produced in coalworker’s pneumoconiosis. Workers exposed to asbestos may develop pleuritic chest pain many years after first exposure as a result of acute asbestos pleurisy.

• dyspnoea on exertion
• Dry, non-productive; frequency increases with progression. (may be absent in early stages. may also become productive if patient develops COPD as a complication)

Question 4

signs

Answer 4

• Examination may be normal.
• Decreased breath sounds in coalworker’s pneumoconiosis or silicosis. End-inspiratory crepitations and clubbing in asbestosis.
• Signs of a pleural effusion or right heart failure (cor pulmonale).

Question 5

investigations

Answer 5

• CXR
• CT scan: Fibrotic changes can be visualized early.
• Bronchoscopy: Visualizes changes. Allows for bronchoalveolar lavage.
• Lung function tests: Restrictive ventilatory defect, impaired gas diffusion.