Pneumoconiosis Flashcards
What is Pneumoconiosis?
Group of fibrosing interstitial lung disease caused by chronic inhalation of mineral dusts
- Simple: Coal workers 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.
What is the epidemiology of Pneumoconiosis?
- Decreasing
- Increasing in Developing countries
- Common in coal and metal workers
What is the Aetiology of Pneumoconiosis?
Inhalation of Metal or Mineral dust
- Silica
- coal
- Beryllium
- (Asbestos)
How does inhalaiton of Silica or coal dust lead to Pneumoconiosis?
- Silica: fine quarz particles are fibrogenic
* Small silica particles inhaled –> get into Alveoli –> Macrophage ingestion + cytolysis –> Brisk, powerful immune response - Coal
* Like Silica: lytic effect on alveolar macrophages leading to release of inflammatory cytokines and fibrosis
What are common serological findings of coal workers pneumoconiosis and silicosis?
- polyclonal hypergammaglobulinemia,
- rheumatoid factor,
- antinuclear antibodies,
- and immune complexes.
How does Beryllium inhalation cause Pneumoconiosis?
T-cell bind to Beryllium leading to change in T-cell peptide binding causing a change in interaction of T-cells with every other antigen
What are risk factors for the development of Pneumoconiosis?
- Occupational Exposure to
- Coal (coal mining)
- Silica (mining, construction, foundry (Glashütte/Gießerei)
- Normally exposure >20 years before presentation
- Beryllium
- Also: genetic predisposition
- Larger communicative dose of inhaled coal or Silica
- Smoking
What are the presenting symptoms of Pneumoconiosis?
Long-time asymptomatic
In more sever disease
- Progressive SOB (on exertion)
- Dry, non-productive progressive Cough (frequency increasing with disease progression)
- Productive if p. also developed COPD
- Chest tightness
- Wheezing
- Symptoms of TB (complication of Silicosis)
What are signs of Pneumoconiosis on chest examination?
Normal unless very advanced disease
- Later: Crackels (fine end-expiratory)
- Prolonged expiration and wheezing
- May be present in silica- and coal-exposed workers who have also developed COPD
- Percussion
- Areas of dull percussion
- due to massive fibrosis (coal and silica)
- Other
- Cyanosis
- Barrel chest
- Weight loss, Fever, night sweats (pulmonary TB –> complication of silicosis)
- Cyanosis
Which Investigations would you do in a patient with susected Pneumoconiosis?
- Imaging
- CXR
- CT
- Spirometry
- Bronchoscopy
- Beryllium lymphocyte proliferation test (if beryllium suspected)
What are the characteristic changes of Silicosis/Coal Workers Pneumoconiosis on a CXR?
- non-calcified, multiple (in the hundreds), rounded opacities in the upper zones
- Egg shell calcification of hilar lymph nodes
–> Progressive into all zones, might conglomerate to form larger occupancies
In CT changes can be visualised earlyer
What are the expected findings on spirometry in a patient with pneumoconiosis?
- Findings of restrictive lung disease
- Reduced FVC / normal FVC1/FVC ratio
- Might also have obstructive changes due to development of COPD
