Interstitial and Occupational Lung Disease (DISEASE MECHANISMS)

Question 1

What is interstitial disease?

Answer 1

Any disease that affects lung insterstitium, interferes with gas transfer and shows a restrictive lung pattern

Question 2

What are the symptoms of ILD?

Answer 2

Breathlessness

Dry cough

Question 3

What type of ILD would a viral infection cause?

Answer 3

Acute ILD

Question 4

What can cause episodic ILD?

Answer 4

Environmental or systemic factors

Question 5

What can cause chronic ILD?

Answer 5

Exposure to an external agent (drug, dust, etc.) or idiopathic

Question 6

What is sarcoidosis?

Answer 6

Multi-system idiopathic non-caseating granulomatous type IV hypersensitivity disease

Question 7

Which tissues does sarcoidosis commonly affect?

Answer 7

Lungs
Lymph nodes
Joints
Liver
Skin 
Eyes

Question 8

Which tissues does sarcoidosis less commonly affect?

Answer 8

Kidneys
Brain
Nerves
Heart

Question 9

What is the common presentation of acute sarcoidosis?

Answer 9

Uveitis
Erythema nosodum
BHL
Arthritis
Parotitis 
Fever

Question 10

What is the common presentation of chronic sarcoidosis?

Answer 10

Lung infiltrates (Alveolitis)Skin infiltrations
Peripheral lymphadenopathy
Hypercalcaemia
Other organ involvement

Question 11

What would be included in the differential diagnosis for sarcoidosis?

Answer 11

Tuberculosis
Lymphoma
Carcinoma
Fungal infection

Question 12

How can you test for sarcoidosis?

Answer 12

CXR
CT scan thorax
Tissue biopsy
Pulmonary function tests
Blood tests

Question 13

What would a CR of a sarcoidosis patient show?

Answer 13

BHL

Question 14

What would a CT scan thorax of a sarcoidosis patient show?

Answer 14

Peripheral nodular infiltrate

Question 15

What would a tissue biopsy of a sarcoidosis patient show?

Answer 15

Non-Caseating granuloma (diagnostic)

Question 16

What type of lung pattern do sarcoidosis patients have?

Answer 16

Restrictive

Question 17

What would be the expected blood test results be a for a sarcoidosis patient?

Answer 17

Increase ACE
Increased Ca
Increased Immunoglobulins

Question 18

How is acute sarcoidosis treated?

Answer 18

Self-limiting
Bed Rest
NSAIDs (e.g. aspirin)

Question 19

How is chronic sarcoidosis treated?

Answer 19

Oral steroid if vital organs affected

Immunosuppressants in severe illness

Question 20

What type of follow-up should sarcoidosis patients receive?

Answer 20

Monitoring of CXR and pulmonary function for years to check for possible relapse

Question 21

What are the indications for corticosteroids in sarcoidosis?

Answer 21

Parenchymal lung disease
Uveitis
Hypercalcaemia
Neurological or cardiac involvement

Question 22

What is extrinsic allergic alveolitis?

Answer 22

Type III hypersensitivity reaction to an antigen

Question 23

What are the causes of EAA?

Answer 23

Farmer’s and Mushroom’s lung (Micropolyspora faeni, Thermoactinomyces vulgaris)
Malt worker’s lung (aspergillus cluvatus)
Bagassosis or sugar worker’s lung (Thermoactinomyces sacchari)
Drugs (Bleomycin, gold, sulphazalanine)

Question 24

What are the clinical features of acute EAA?

Answer 24

Cough
Breathless
Myalgia
Fever/Pyrexia
Crackles
Hypoxia

Question 25

How is acute EAA treated?

Answer 25

``` Remove allergen Give O2 (35-60%) Then oral prednisolon (40mg/24h PO) followed by reducing dose ```

Question 26

What tests can be undertaken for acute EAA?

Answer 26

Blood - FBC, increased ESR, ABGs, positive serum precipitins (indicate exposure only) CXR - upper zone mottling/consolidation, hilar lymphadenopathy PFTs - restrictive pattern

Question 27

What would cause chronic EAA?

Answer 27

Recurrent low antigen exposure

Question 28

What are the signs and symptoms of chronic EAA?

Answer 28

``` Progressive Dyspnoea Cough Crackles Weight loss Exertion dyspnoea Type I respiratory failure Cor pulmonale CXR - fibrosis (mainly upper zones) PFTs - restrictive ```

Question 29

How can a diagnosis of chronic EAA be made?

Answer 29

History of exposure Positive serum precipitins Lung biopsy if doubt BAL (Bronchial alveolar lavage) shows increased lymphocytes & mast cells

Question 30

How is chronic EAA treated?

Answer 30

Avoid exposure to allergen or wear facemark for positive pressure helmet Long-term steroids often achieve CXR + physiological improvement

Question 31

What is idiopathic pulmonary fibrosis?

Answer 31

``` Unknown origin Imbalance of fibrotic repair system ?related to gastric reflux Not inflammatory More common in smokers ```

Question 32

What are secondary causes of pulmonary fibrosis?

Answer 32

``` Rheumatoid SLE Systemic sclerosis Asbestos Drugs (amiodarone, bleomycin, penicillamine, nitrofurantoin, methotrexate) ```

Question 33

What is the clinical presentation of IPF?

Answer 33

Progressive dyspnoea | Dry cough

Question 34

What is found O/E for IPF?

Answer 34

Clubbing | Bilateral fine inspiratory crackles

Question 35

What is found Ix for IPF?

Answer 35

Restrictive pattern on PFTs CXR - bilateral infiltrates, reduced lung volume, bilateral zone reticulonodular shadows, honeycomb (if advanced) CT - reticulonodular fibrosis shadowing, worse at lung bases and periphery / Traction bronchiectasis, honey-combing / cystic changes Lung biopsy (only if CT not diagnostic Bloods: ABGs (low PaO2, high PaCO2 if severe) / CRP increased, increased immunoglobulins / ANA (30% TVC) / Rheumatoid factor (10% +ve)

Question 36

What would have to be excluded from the differential to confirm IPF?

Answer 36

Occupational disease (asbestosis, silicosis) Connective tissue disease (Rha, scleroderma, Sjorgens disease, SLE) LVT Sarcoidosis EAA

Question 37

How is the diagnosis of IPF made?

Answer 37

Combination of history, examination and HRCT scan (radiology)

Question 38

What is the pathology of IPF?

Answer 38

Usual interstitial pneumonia pattern: heterogeneous fibres fibrosis in alveolar walls with fibroblastic foci and destruction of architecture causing honeycombing. Inflammation is minimal

Question 39

How is IPF treated?

Answer 39

Antifibrotic drugs (slow progression, no reversal) are in clinical trials No steroids or anti-inflammatories (unless doubt diagnosis) lung transplant Best supportive care: O2 if hypoxic, pulmonary rehabilitation, opiates, palliative care input

Question 40

What is the prognosis of IPF patients?

Answer 40

50% 5yr survival rate | Range 1-20 years

Question 41

What does coal worker's simple pneumoconiosis show on CXR?

Answer 41

Abnormality

Question 42

What is the effect of coal worker's simple pneumoconiosis on lung function?

Answer 42

Often associated with COPD | No impairment of lung function

Question 43

What does coal worker's complicated pneumoconiosis cause?

Answer 43

Progressive massive fibrosis (PMF) Dyspnoea Eventually cor pulmonale

Question 44

What kind of lung pattern do patient's with coal worker's complicated pneumoconiosis have?

Answer 44

Restrictive

Question 45

What causes chronic bronchitis?

Answer 45

Coal dust + smoking

Question 46

What is Caplan's syndrome?

Answer 46

Association between rheumatoid arthritis, pneumoconiosis, and pulmonary rheumatoid nodules

Question 47

What causes silicosis?

Answer 47

Inhalation of silica particles (exposure to quartz - usually over long time

Question 48

What occupations is silicosis associated with?

Answer 48

Mining Foundry workers Glass workers Boiler workers

Question 49

How does simple pneumoconiosis silicosis present?

Answer 49

Few symptoms | CXR - egg-shell calcification of hilar nodes

Question 50

How does chronic pneumoconiosis silicosis present?

Answer 50

Progressive dyspnoea Increased incidence of TB CXR - diffuse military or nodular patterning upper and mid zones + egg-shell calcification of hilar nodes Spirometry -- restrictive pattern

Question 51

What causes baritosis?

Answer 51

Exposure to barium

Question 52

What are asbestos related pleural diseases?

Answer 52

Benign pleural plaques Acute asbestos pleuritis Pleural effusion and diffuse pleural thickening Malignant mesothelioma

Question 53

What are non-pleural asbestos related diseases?

Answer 53

Asbestosis | Bronchial carcinoma

Question 54

What symptoms do benign pleural plaques cause?

Answer 54

None

Question 55

How does acute asbestos pleuritis present?

Answer 55

Fever Pain Bloody pleural effusion

Question 56

How does pleural effusion and diffuse pleural thickening due to asbestosis present in terms of spirometry?

Answer 56

Restrictive impairment

Question 57

What is malignant mesothelioma?

Answer 57

Incurable pleural cancer

Question 58

How does malignant mesothelioma present?

Answer 58

Chest pain | Pleural effusion

Question 59

What is the average prognosis for malignant mesotheliomas

Answer 59

2 years

Question 60

What colour is chrysotile asbestos?

Answer 60

white

Question 61

What colour is amosite asbestos?

Answer 61

brown

Question 62

What colour is crocidolite asbestos?

Answer 62

blue

Question 63

In which order do the different colours of asbestos rank for increasing fibrogenicity?

Answer 63

White - brown - blue

Question 64

What are the clinical features of asbestosis?

Answer 64

``` Progressive dyspnoea Clubbing Fine end-inspiratory crackles Pleural plaques Increased risk of bronchial adenocarcinoma and mesothelioma ```

Question 65

The fact that smokers that have been exposed to asbestos have a higher risk for lung cancer than the sum of asbestos and smoker risk is called the ______?

Answer 65

Synergistic effect

Question 66

Which occupations are related to asbestos exposure?

Answer 66

Mining Construction Ship-building Boilers and piping