19. Interstitial lung disease

Question 1

What is interstitial lung disease?

Answer 1

A grouped term for conditions that affaect the lung parenchyma causing chronic inflmmation and interstitial fibrosis.

Question 2

What are some examples of interstitial lung disease?

Answer 2

sarcoidsis
Hypersensitivity pneumonitis
Idiopathic pulmonary fibrosis

Question 3

How can interstitial lung diseases be classified?

Answer 3

Those with known causes:

Cotton workers lung (byssinosis), GORD, infection (TB)

Those with associated systemic disorders:

RA, SLE, Sjorgens sydrome,UC

Idiopathic:

Cryptogenic organizing pneumonia

Question 4

What pathological changes occur in interstitial lung diseases?

Answer 4

Type II epithelial cell hyperplasia
Type II pneumocyte hyeprplasia
Fibrosis and remodeling of the interstitium
Chronic inflammation

Question 5

What is extrinsic allergic alveolitis?

Answer 5

Also known as hypersensitivity pneumontiis repetitive inhalation of allergens causes acute infiltrates in the alveoli and in chronic exposure forms granulomas and obilterative bronchiolitis occurs

Question 6

What are the causes of of hypersensitivity pneumontiis (EAA)?

Answer 6

Bird fancier’s lung (Proteins in bird droppings)

Farmer’s and mushroom workers lung (Micropolyspora faeni, thermoactino-myces vulgaris)

Malt workers lung (aspergillus clavatus)

Sugar worker’s lung (Thermoactinomyces sacchari)

Question 7

What are the clinical features of acute extrinsic allergic alveolitis?

Answer 7

Fevers, rigors, myalgia, dry cough, dypnoea, fine bibasal crackles

Question 8

What are the clinical features of chronic extrinsic allergic alveolitis?

Answer 8

Finger clubbing, increasing dyspnoea, weight loss, exertional dyspnoea, type I resp failure, cor pulmonale

Question 9

What are the tests for acute etrinsic alveolitis?

Answer 9

FBC, ESR
ABG
Serum antibodies
CXR
Lung function tests

Question 10

What are the tests for chronic acute extrinsic alveolitis?

Answer 10

Serum antibodies,
CXR (honeycomb lung)
Lung function tests
Bronchoalveolar lavage- increased lymphs and mast cells

Question 11

What is the acute management of acute extrinsic alveolitis?

Answer 11

Remove allergen and give oxygen

Predinosolone, reducing course

Question 12

What is the chronic management of chronic extrinsic allergic alveolitis?

Answer 12

Allergen avoidance (wear mask, positive pressure suit
Long term steroids
Compensation is often available

Question 13

What is the commonest cause of interstitial lung disease?

Answer 13

Idiopathic pulmonary fibrosis

Question 14

What causes idiopathic pulmonary fibrosis

Answer 14

Nobody knows

Question 15

What are the symptoms of idiopathic pulmonary fibrosis?

Answer 15

Dry cough, exertional dyspnoea, malaise

Weight loss, arthralgia

Question 16

What are the signs of idiopathic pulmonary fibrosis

Answer 16

Cyanosis
Finger clubbing
Fine end inspiratory crepitations

Question 17

What are the complications of idiopathic pulmonary fibrosis?

Answer 17

Respiratory failure

Increased risk of lung cancer

Question 18

What tests can be done for idiopathic pulmonary fibrosis

Answer 18

ABG
CRP,immunoglobulins, rheumatoid factor
CXR- bilateral retiulo-nodular shadow, honeycomb lung
BAL- raised lymphocytes good, raised neut/eosin- bad
Lung biopsy- for diagnosis

Question 19

Describe the management of idiopathic pulmonary fibrosis

Answer 19

Supportive care, pulmonary rehabilitation, opiates

Palliative care

Question 20

What is the prognosis for IPF?

Answer 20

50% 5yr survival rate

Question 21

What new treatment is showing signs?

Answer 21

Nintedanib and pirfenidone (immunosuppresant and biologic)