Interstitial lung disease

Question 1

What is interstitial lung disease?

Answer 1

umberella term to describe conditions that affect the lung parenchyma (lung tissue) causing inflammation and fibrosis

Question 2

what is fibrosis?

Answer 2

replacement of the normal elastic and functional lung tissue with scar tissue. it is stiff and does not function as effectively

Question 3

how is interstitial lung disease diagnosed?

Answer 3

high resolution CT scan of thorax= HRCT shows ‘ground glass’ appearance

lung biopsy= histology

Question 4

how is interstitial lung disease managed?

Answer 4

Remove or treat the underlying cause
Home oxygen where they are hypoxic at rest
Stop smoking
Physiotherapy and pulmonary rehabilitation
Pneumococcal and flu vaccine
Advanced care planning and palliative care where appropriate
Lung transplant is an option but the risks and benefits need careful consideration

Question 5

types of interstitial lung disease

Answer 5

1. idiopathic pulmonary fibrosis
2. drug induced pulmonary fibrosis
3. secondary pulmonary fibrosis
4. hypersensitivity pneumonitis
5. cryptogenic organising pneumonia
6. asbestosis

Question 6

idiopathic pulmonary fibrosis

Answer 6

this is a condition where you have progressive pulmonary fibrosis but there is no clear cause.

symptoms: insidious onset of shortnesss of breath and dry cough >3 months.

affects adults >50 y/o (life exp 2-5 years)

O/E
bibasal fine inspiratory crackles
finger clubbing

Question 7

idiopathic pulmonary fibrosis management

Answer 7

to slow progression:

Pirfenidone is an antifibrotic and anti-inflammatory

Nintedanib is a monoclonal antibody targeting tyrosine kinase

Question 8

drug induced pulmonary fibrosis

which drugs?

Answer 8

Amiodarone
Cyclophosphamide
Methotrexate
Nitrofurantoin

*there are several

Question 9

secondary pulmonary fibrosis

Answer 9

pulmonary fibrosis occurring secondary to other conditions

RA, SLE, progressive systemic sclerosis, IBD, primary biliary cholangitis

these include:
Alpha-1 antitripsin deficiency
Rheumatoid arthritis
Systemic lupus erythematosus (SLE)
Systemic sclerosis

Question 10

what is hypersensitivity pneumonitis

Answer 10

aka extrinsic allergic alevolitis

type III hypersensitivity reaction to an environmental allergen.
causes the parenchymal inflammation and destruction I people that are sensitiv to that allergen

diagnosis:
PCR, blood culture, urinary antigens
bronchoalveolar lavage. collect cells from arrays during bronchoscopy (wash airways with fluid). when tested, shows raised lymphocyte and mast cells

O/E wheeze, crackles, squeeks

mx: remove allergen, O2, steroids

Question 11

example of specific causes of hypersensitivity pneumonitis

Answer 11

Bird-fanciers lung is a reaction to bird droppings

Farmers lung is a reaction to mouldy spores in hay

Mushroom workers’ lung is a reaction to specific mushroom antigens

Malt workers lung is a reaction to mould on barley

farmers
sauna/ventilation
birds/poultry
grain/flour
wood
vets/animal handlers
textile
plastics

Question 12

cryptogenic organising pneumonia

Answer 12

previously known as bronchiolitis obliterans organising pneumonia

this is a focal area of inflammation in the lung tissue. can be idiopathic or triggered by infection, inflammation, meds, radiation or environmental toxins/allergens

symptoms: SOB, cough, fever, lethargy

CXR: focal consolidation
lung biopsy

tx: systemic corticosteroids

Question 13

asbestosis

Answer 13

mined mineral
lung fibrosis related to inhalation of asbestos. ‘fibrogenic’ (causes the lungs to fibres) and oncogenic (causes cancer)

asbestosis inhalation causes:
1. Lung fibrosis
2. Pleural thickening and pleural plaques (holly leaves)
3. Adenocarcinoma
4. Mesothelioma (low exposure to asbestos toxins) prognosis 12-18 months
not very responsive to chemotherapy) 
adenocarcinoma (high exp)
5. bronchogenic carcinoma

large pleural plaques (holly leaves)
acute asbestosis pleurisy
diffuse plural fibrosis (thickening of pleura on the viscera of lung)
bronchial carcinoma

Question 14

budgie lungs (not the same as bird fancier lungs)

Answer 14

chlamydia psittaci
atypical pneumonia’s

won’t necessarily have any crackles/ signs

they do not have a standard wall so penicillins do not work
use non penicillins- doxycycline, clarithromycin, quinolones

Question 15

worsening asthma

Answer 15

occupational
smoking
mould
pet dander (cat= saliva, dog=fur)
NSAID use 
catameniol asthma (worse before periods as there is less progesterone- which is usually a smooth muscle relaxant) (progesterone= pro gestation)

Question 16

silicosis

Answer 16

fine particles.
takes time for them to settle out

air flow is lower at the top of lungs so this is where the the silicosis particles sits.

Question 17

burkholderia pseudomallei

Answer 17

gram negative
community acquired pneumonia in thailiand
multi-resistant

causes a necrotising severe pneumonia

most common cause of CAP in UK is streptococcus pneumonia

Question 18

asbestosis (2)

Answer 18

development of fibrosis interstitially. insidious 40 years after exposure. microfibre that was used as instillation. high exposure (Dock Worker) (teachers) (break mechanic)

XRAY- plaques

investigate:
CT honeycombing, sub pleural lines

Question 19

asbestosis histopathology

Answer 19

microphages ingest fibers- collagen deposition
brown IRON blobs
irreversible dilation of bronchioles- signet ring sign
infolding of the ring

Question 20

idiopathic pulmonary fibrosis

Answer 20

a specific form of chronic progressive lung fibrosis of uknown origin

pathophysiology: fibrosis occurs in response to damage in the lung from acid reflux, viruses (EBV, HSV, hep C) environmental factors (dust, wood, textiles, metal, stone, cattle,
farming, genetic)

progressive exertion dyspnoea, non productive cough, clubbing, fine end inspiratory crepitations at lung bases.

Question 21

idiopathic pulmonary fibrosis symptoms

Answer 21

SOB on exertion or at rest
cough +/- sputum
fatigue
cyanosis
finger clubbing
fine end inspiratory crackles

Question 22

IPF investigations

Answer 22

blood tests
environmental and occupational exposure

PEFR- restrictive lung defect

ABG type I resp failure wiht hypoxaemia and normal or low co2

ANA
RF
anit CCP
myositosis 
CXR- small lung volumes, interstitial shadowing most marked at the bases and peripheries (lower zone fibrosis)

xray of reticular pattern
lun markings worse on base

CT of thorax (confirms distribution of fibrosis)

Lung function test (restrictive)
surgical bipsy
bronchoalveolar lavage

*histopathology: honeycombing, minimal cellular inflammation and regoins of proliferating myofirboblasts.

Question 23

IPF management

Answer 23

non pharmacoogical- pulmonary rehabilitation (Exercise/educational)

pharmacological
antifibrotic drugs- pirfenidone, nintedanib slow rate of scaring
O2 therapy
PPI
NAC oral n aetyl L cysteine

surgical- lung transplantation

various new regimes- high dose steroids, immunosuppressants, azathioprine, cyclophosphamide, cyclosporin

Question 24

hypersensitive pneumonitis chronic

Answer 24

chronic
no hx of acute eps
long onset of symptoms, lower lung tissue, resp crackles, emphysema, honeycombing, clubbing, pneumoconiosis

siliac, coal, iron, inorganic
restrictive fibrosis
long time 10+

Question 25

acute attack of bird fanciers lung

Answer 25

4-6 hrs after exposure
fever, inflammation response, cough, rash
ground glass opacities
poorly formed granulomatous
resolves in a few days

subacute attack
gradual onset
severe, lasts longer
no fever/chills
weight loss and loss of appetite
pleuritic pain
pain on inspiration
opacities in lower ones

Question 26

cell type and associated disease

Answer 26

haemosiderine laden macrophage= alveolar bleeding

high CD4= sarcoidosis

eosinophils= allergic bronchopulmonary aspergillosis

neutrophils= pneumonia, interstitial lung disease

marked lymphocytes= hypersensitivity pneumontis

Question 27

histological triad of….

Answer 27

hypersensitivity pneumonitis (farmers lung) mouldy hay or other materials. interstitial inflammation, chronic bronchitis, two foci of non-necrotising granuloma

aspergillosis
lung biopsy may show hyphae with vascular invasion surrounding tissue necrosis

sarcoidosis: schumann bodies, calcified rounded laminated concentration inside the non-caseating granuloma. formed of body giant cells (star shaped inclusions ‘asteroid bodies’)

histiocytosis X - langerhan cells

TB- caveating granulomas in the lung parenchyma. fibrosis in later stages. Ziehl Neelsen staining reveals acid-fast bacill.

Question 28

pleural plaques (caused by asbestosis)

Answer 28

asymptomatic
asbestos exposure
irregular well defined calcified lesions that may appear as dense lines in the pleura when seen from lateral views or like ‘holly leaves’ from anterior views

Question 29

mesothelioma (from asbestos exposure)

Answer 29

development of malignant mesothelioma is strongly associated with inhalation of asbestos fibres.

breathlessness, weight loss, lung is appeared to be ‘strangled’. but he tutor, chest pain

Question 30

bronchogenic exposure (from asbestos exposure)

Answer 30

asbestos exposure and cigarette smoking

weight loss
anorexia
haemoptysis

small tumor