pulmonary fibrosis + occupational disease

Question 1

types of fibrosis commonly affecting the upper zones

Answer 1

(less common stuff)
- hypersensitivity pneumonitis
- coal workers pneumoconiosis
- silicosis
- sarcoidosis
- anykylosing spondylitis
- histiocytosis
- tuberculosis

radiation induced - 6-12mnths post radiotherapy

Question 2

fibrosis predominantly affect lower zones

Answer 2

(commoner stuff)
- idiopathic pulmonary fibrosis
- SLE
- abestosis

drugs
- amiodarone
- bleomycin
- methotrexate

Question 3

idiopathic pulmonary fibrosis

Answer 3

chronic lung condition characterised by progressive fibrosis of the interstitium of the lungs
- with no underlying cause

ages 50-70yrs - commoner in men

Question 4

pulmonary fibrosis presentation

Answer 4

progressive exertional dyspnoea
dry cough
clubbing

bibasal fine end-inspiratory crepitations on auscultation

Question 5

diagnosing pulmonary fibrosis

Answer 5

high resolution CT scan = definitive diagnosis

spirometry = restrictive
- FEV1 - normal/decreased
- FVC decreased
- FEV1/FVC increased

CXR
impaired gas exchange - reduced transfer factor (TLCO)

Question 6

pulmonary fibrosis on CXR

Answer 6

bilateral interstitial shadowing - small, irregular, peripheral opacities

“ground glass” - progressing to -> “honeycombing”

Question 7

management of pulmonary fibrosis

Answer 7

pulomonary rehab
many will need supplementary oxygen + lung transplant

not many drugs help
- pirfenidone (anti-fibrotic)

Question 8

pulmonary fibrosis prognosis

Answer 8

poor, average life expectancy 2-4yrs

Question 9

drugs causing lung fibrosis

Answer 9

amiodarone
cytotoxic agents - bleomycin, busulphan

anti-rheumatoid drugs - methotrexate, sulfasalazine

nitrofurantoin
dopamine receptor agonists - bromocriptine, cabergoline, pergolide

Question 10

silicosis

Answer 10

a fibrosing lung disease caused by inhalation of fine particles of crystalline silicon dioxide (silica)

risk factor for developing TB
(silica is toxic to macrophages)

Question 11

occupations at risk of silicosis

Answer 11

• mining
• slate works
• foundries
• potteries

Question 12

silicosis features

Answer 12

upper zone fibrosing lung disease

“egg-shell” calcification of hilar lymph nodes

Question 13

coal workers pneumoconiosis

Answer 13

long term exposure to coal dust particles, long lead time between first exposure + development of disease (15-20yrs)

CXR = upper zone fibrosis
spirometry = restrictive

Question 14

what benign changes to the lungs can asbestos cause

Answer 14

pleural plaques - do NOT undergo malignant change
- occur after latent period of 20-40yrs

pleural thickening, diffuse

Question 15

asbestosis features

Answer 15

severity linked to length of exposure (in contrast to mesothelioma)

lower lobe fibrosis
- dyspnoea, reduced exercise tolerance
- clubbing
- bilateral end-inspiratory crackles

restrictive pattern + reduced gas transfer

mx = conservative

Question 16

mesothelioma

Answer 16

malignant disease of the pleura
- crocidolite (blue) asbestos is most dangerous form
- v little exposure can cause

Question 17

most assoc cancer with asbestos

Answer 17

lung cancer
- more so than mesothlioma

has synergistic effect with cigarette smoke –> cessation v important in mx

Question 18

definitive diagnosis of mesothelioma

Answer 18

thoracoscopy