Hypersensitivity pneumonitis

Question 1

what is it?

Answer 1

Granulomatous chronic response to lung injury

Question 2

Aetiology

Answer 2

• actinomycetes bacteria
• bird feathers/poo
• animal fur
• Hay
• Sugar cane mould
• coffe bean dust
• fungi: aspergillum species
• chemical

Question 3

Development

Answer 3

XS response to a pathogen

• leads to the development of type 3 and type 4 hypersensitivity complexes
• type 3 leads to inflammation and necrosis of the alveoli
• type 4: granulomatous formation which lead to the development of fibrin so fewer functioning alveoli

Question 4

Signs of Acute/Chronic

Answer 4

Acute:
-tachypnea 
-crackles 
-wheeze
Chronic:
-crackles/wheeze

Question 5

Symptoms of acute/chronic

Answer 5

Acute:

• fever
• SOB
• cough
• chest tightness
• chills 4-9 hours after exposure

Chronic:

• SOB
• cough
• Malaise
• Respiratory failure

Question 6

Investigation

Answer 6

CXR- diffuse infiltrative
Pulmonary function test
Bronchial biopsy
Bronchoalveolar lavage

Question 7

Bronchoalveolar lavage

Answer 7

Bronchoscopy and squeeze fluid into lungs
Aspiration:
-increase lavage
-increase mast cells

Question 8

Histology

Answer 8

BIGGEST
-immune complexes 3 and 4 
-soft centracinar epithelia granulomata 
LESS:
-foamy  histiocytes 
-interstitial pneumonitis 
-Bronchiolitis obliterates

Question 9

Bronchiolitis obliterans

Answer 9

popcorn lung

obstruction of the smallest airways of the lung due to inflammation

Question 10

Also known as?

Answer 10

Farmer’s lung

Question 11

Disease of which part of the lung?

Answer 11

upper lung