Interstitial lung diseases

Question 1

What are the clinical features of interstitial lung diseases?

Answer 1

Dyspnoea
Non productive paroxysmal cough
Abnormal breath sounds
Restrictive pulmonary spirometry

Question 2

What are the broad classifications of interstitial lung diseases and which fall into which?

Answer 2

Those of known cause:
-drugs
-hypersensitivity
-Occupational
-Infections
Those associated with systemic disorders:
-Sarcoidosis
-Rheumatoid arthritis
-SLE
Idiopathic:
-Idiopathic pulmonary fibrosis
-Cryptogenic organising pneumonia
-Non-specific interstitial pneumonitis

Question 3

What is the pathogenesis of hypersensitivity pneumonitis and what are the common causes?

Answer 3

There is repeated exposure to an allergen causing repeated inflammation and fibrosis of the airways.
Commonly caused by proteins in bird droppings (bird fanciers)
Farmers lung - fungal spores from hay

Question 4

What are the common clinical features of hypersensitivity pneumonitis?

Answer 4

Inital exposure causes fever, dyspnoea, fine bibasal crackles
Chronically it causes finger clubbing, increasing dyspnoea, type 1 respiratory failure

Question 5

What are the tests for hypersensitivity pneumonitis?

Answer 5

Acutely - bloods look for neutrophilia, serum antibodies, lung function tests for reversible restrictive defect.
Chronically - CXR - upper zone fibrosis, honeycomb lung - CT chest - ground glass appearance, fibrosis, nodules

Question 6

What is the management of hypersensitivity pneumonitis?

Answer 6

Avoid allergen!
Acutely give prednisoline
Chronic - Long term steroids can be used but mainly avoid with face mask etc.

Question 7

What are upper zone causes of fibrotic shadowing on cxr?

Answer 7

TB
Hypersensitivity pneumonitis
Radiotherapy
Ankylosing spondylitis
Progressive massive fibrosis (pmf)

Question 8

What are the causes of mid zone fibrotic shadowing on cxr?

Answer 8

Sarcoidosis

Histoplasmosis

Question 9

What are causes of lower zone fibrotic shadowing on cxr?

Answer 9

Idiopathic pulmonary fibrosis

Asbestosis

Question 10

What are the symptoms of idiopathic pulmonary fibrosis?

Answer 10

Dyspnoea, dry cough, malaise, decreased weight

Question 11

What are the signs of idiopathic pulmonary fibrosis?

Answer 11

Clubbing
Cyanosis
Fine end-inspiratory crepitations

Question 12

What are the investiagtions for idiopathic pulmonary fibrosis?

Answer 12

Bloods - ABG, increased CRP, Increased immunoglobulins, ANA in 30%, rheumatoid factor in 10%
CXR - lower zone reticulonodular shadowing, similar changes on CT
Spirometry shows restrictive disease and decreased transfer factor
Lung biopsy shows usual interstitual pneumonia (UIP)

Question 13

What is the management of idiopathic pulmonary fibrosis?

Answer 13

Supportive care, oxygen, pulmonary rehab, opiates, palliative care
Biologics can be used in fit patients (Nintendanib)
Lung transplantation
High dose steroids should not be used unless the diagnosis of IPF is in doubt.

Question 14

What is the pathogenesis of coal workers pneumoconiosis?

Answer 14

This is when macrophages try to digest coal dust and die releasing enzymes and causing fibrosis

Question 15

What are the clinical features of coal workers pneumoconiosis?

Answer 15

Asymptomatic but commonly coexists with chronic bronchitis

CXR shows many round opacities

Question 16

What is the management of coal workers pneumoconiosis?

Answer 16

Avoid coal dust, treat co existing bronhitis

Question 17

What is progressive massive fibrosis and what are its symptoms?

Answer 17

This is progression of coal workers pneumoconiosis and causes progressive dyspnoea, fibrosis and everntually cor pulmonale

Question 18

What are the clinical features of silicosis?

Answer 18

The particles are very fibrinogenic and cause progressive dyspnoea and increased incidence of TB
CXR shows nodular pattern in upper and mid zones
Spirometry shows restrictive pattern

Question 19

What is the management of silicosis?

Answer 19

Avoid exposure to silica

Question 20

What are the clinical features of asbestososis?

Answer 20

Progressive dyspnoea
Fine end inspiratory crackles
Clubbing
Increased risk of bronchial carcinoma and mesothelioma