Occupational lung diseases Flashcards
What is meant by occupational lung diseases?
Diseases of the lung that are caused by a person’s occupation.
What type of things might cause occupational lung diseases?
Fumes
Dust
Gas or vapour
Mists or aerosols
Occupational lung diseases present can present themselves immediately or decades later.
Give some examples of OLDs that present themselves after:
- minutes
- years
- decades
Minutes:
- Direct injury: acute irritant asthma
- Infection: silicotuberculosis
- Allergy: asthma
Years:
- Chronic inflammation: COPD, bronchitis
- Destruction of lung tissue: emphysema
Decades:
- Lung or pleural thickening: asbestosis
- Carcinogenesis: lung, mesothelioma
Which are the 2 most common occupational lung disease?
Non-malignant pleural disease
Mesothelioma
There are 2 types of occupational asthma. What are they?
Which is most common?
- Asthma induced by allergy to an agent inhaled at work
- Asthma induced by accidental irritant exposure at work
1 is most common
What type of agents can trigger occupational asthma?
Flour in a bakery
Animal dander
Car fumes
Many more
What sort of occupations can cause occupational COPD?
Mining, any job that involves the inhalation of dust or fumes
What is the non-UK name for Extrinsic Allergic Alveolitis (EAA)?
Hypersensitivity pneumonitis
What is EAA? (describe the disease not just what it stands for?
Extrinsic Allergic Alveolitis
Diffuse, granulomatous inflammation of the lung parenchyma and airways
That occurs in people who have been sensitised by repeated inhalation of certain antigens at work or in their environment
List some causes of EAA, and their specific names.
Bird fancier’s lung:
- proteins in bird dropping
Farmer’s lung:
- exposure to mouldy hay
Malt worker’s lung:
- Exposure to mouldy malt
Many more.
EAA exists in 3 different phases/stages?
Acute
Sub-acute
Chronic
Describe acute EAA?
- Clinical features
- Timing
A self-limiting febrile response
Occurs 4-8 hours post exposure
Fever Rigors Myalgia Cough Dyspnoea Crackles Flu-like illness
Describe sub-acute EAA?
- Clinical features
- Timing
Less severe, gradual onset
Intermittent, repeated acute attacks
Productive cough Dyspnoea Fatigue Anorexia Weight loss
Describe chronic EAA?
- Clinical features
- Timing
Irreversible pulmonary fibrosis
If allergen is removed completely, there is little improvement of symptoms
Increasing dyspnoea
Weight loss
Type I respiratory failure
Cor pulmonale
What investigations would you do for acute EAA?
Blood: neutrophilia, raised ESR
CXR: Upper-zone mottling/consolidation
Lung function:
Restrictive lung disease (low FVC, high FEV1:FVC)
What investigations would you do for chronic EAA?
Blood: serum antibodies will be raised in some people
CXR: Upper-zone fibrosis, honeycomb lung
Lung function:
Restrictive lung disease (low FVC, high FEV1:FVC)
Bronchoalveolar lavage:
Fluid shows raised lymphocytes and mast cells
What is a bronchoalveolar lavage?
A bronchoscope is passed through the mouth or nose into the lungs
Fluid is squirted into a small part of the lung and then collected for examination.
What is the pathogenesis of silicosis?
Inhalation of silica particles which are very fibrotic
Silica particles can embed themselves into alveolar sacs and ducts in the lungs impairing gas exchange
Macrophages ingest the silica particles setting off an inflammation response
This then stimulates fibroblasts to proliferate and produce collagen around the silica particle, thus resulting in fibrosis
What are asbestos-related lung diseases?
Inhalation of asbestos fibres which causes various problems in the lungs
What problems can exposure to asbestos cause?
Benign pleural disease: pleural plaques, pleural thickening
Asbestosis: pulmonary fibrosis
Cancer: lung + mesothelioma
What 2 types of asbestos are there?
Amphiboles
Serpentine
What is the most common problem caused by asbestos exposure?
Pleural plaques
What is the latency period of asbestos-related lung diseases?
About 30 years
What are pleural plaques?
Calcified layers of collagen found on the pleura
Completely harmless
No symptoms
Not pre-malignant
