Pneumoconiosis

Question 1

Define:

Answer 1

Fibrosing interstitial lung disease caused by chronic inflammation of mineral dusts.

Question 2

Aetiology:

Answer 2

Caused by inhalation of:

• Coal dust
• Asbestos
• Silica

Mineral particles taken up by the macropahges that then die and release enzymes leading to inflammation and fibrosis.

Question 3

Risk factors:

Answer 3

Occupational exposure (coal mining, quarrying, iron and steel foundries, stone cutting, sandblasting, insulation industry, plumbers, ship builders)

Risk is dependent on extent of exposure and the size/shape of particles

Individual susceptibility is also important

Co-factors such as smoking and TB also contribute

Question 4

Epidemiology:

Answer 4

Increasing in developing countries

Question 5

Symptoms:

Answer 5

May be asymp and spotted on CXR

Insidious onset shortness of breath

Dry cough

Black sputum (melanoptysis) - produced occasionally in coalworker’s pneumoconiosis

Pleuritic chest pain (due to acute asbestos pleurisy) - in patients exposed to asbestos

Question 6

Signs:

Answer 6

Examination may be NORMAL

Coalworker’s pneumoconiosis and silicosis:
o Decreased breath sounds

Asbestosis:
o End-inspiratory crackles
o Clubbing

Signs of pleural effusion or right heart failure (cor pulmonale)

Question 7

Investigations:

Answer 7

• CXR
o Simple: micronodular mottling
o Complicated:
 Nodular opacities in upper lobes
 Micronodular shadowing
 Eggshell calcification of hilar lymph nodes (characteristic of silicosis)
 Bilateral lower zone reticulonodular shadowing and pleural plaques (in asbestosis)

CT Scan - fibrotic changes can be visualised early

Bronchoscopy - allows visualisation and bronchoalveolar lavage

Lung Function Tests - restrictive pattern