Respiratory: Interstitial lung disease

Question 1

How does interstitial lung disease affect a patient?

Answer 1

Ventilation - stiff lungs
Diffusion decreases
Perfusion - capillaries get destroyed

Question 2

What is the pattern of the airflow in interstitial lung disease?

Answer 2

Restrictive pattern

Question 3

What are the symptoms of interstitial lung disease?

Answer 3

Chronic cough and shortness of breath

Clubbing, cyanosis, tachycardia, tachypnoea

Question 4

What is idiopathic pulmonary fibrosis?

Answer 4

Commonest cause of ILD
Presents at 60-80yrs and the median survival is 3yrs
It is diagnosed by CT

Question 5

What are the effects of asbestos on the lungs?

Answer 5

Can get asbestos plaques (thickening of pleura) or diffuse pleural thickening (whole pleura)

• asbestosis (ILD) - no treatment
• malignant mesothelioma
• bronchogenic lung cancer
• benign asbestos pleural effusions

Question 6

What drugs can cause interstitial lung disease?

Answer 6

Methotrexate (used to treat rheumatoid arthritis and ILD)
Amiodarone (used to treat arrhythmias)
Nitrofurantoin (used in UTI prophylaxis)
Chemotherapy

Question 7

What is sarcoidosis?

Answer 7

A rare condition causing non-caseating granulomas to form anywhere on the body but mostly affects skin and lungs. Alveoli contain lots of macrophages and lymphocytes.
Presents at any age but most common in 30s and 40s. Get shortness of breath and a chronic dry cough.

Question 8

What is interstitial lung disease?

Answer 8

Development of fibrous tissue in the interstitium making the lungs less compliant. This increases the diffusion distance.

Question 9

What can cause extrinsic allergic alveolitis?

Answer 9

Can be acute:
Known as farmers lung - antigen inhaled from mouldy hay causes influenza like illness and inspiratory crackles.

Can be chronic:
Known as bird fanciers lung
Exposure to some of the allergens in bird dropping and feathers causes granulomas to form in the lungs. there is malaise, breathlessness and inspiratory crackles

Question 10

What is fibrosing alveolitis?

Answer 10

An idiopathic progressive inflammatory condition causing increased activated alveolar macrophages, increased neutrophils and eosinophils.
Treated with high dose oral steroids
Progressive shortness of breath and dry cough

Question 11

What are some occupations that can cause lung diseases?

Answer 11

Lab workers exposed to rat urine - asthma
Construction workers exposed to asbestos
Farmers and pigeon fanciers - alveolitis
Coal miners - nodular fibrosis