Hypersensitivity Pneumonitis

Question 1

What is hypersensitivity Pneumonitis?

Answer 1

A combined type 3/4 hypersensitvity reaction to foreign antigens leadin to formation of soft centriacinar epitheloid granulomas and intersitial pneumonitis with fibrosis.

Question 2

What is a common name for hypersensitivity pneumonitis?

Answer 2

Bird Fancier’s Lung

Question 3

What are the symptoms of HP?

Answer 3

Acute:

• Fever & chills
• Dry Cough
• Myalgia
• Crackles
• Tachypnoea
• Wheeze

Chronic:

• Malaise, fatigue, weight loss
• SOB, Cough
• Tachypnoea
• Type 1 Resp. failure.

Question 4

What tests can be done for HP?

Answer 4

CXR
Lun function Tests looking for restrictive pattern.
Biopsy

Question 5

What would a HP biopsy show?

Answer 5

expansion of the interstitium along with some multinucleated giant cells or granulomas.

Question 6

What antigens commonly cause HP?

Answer 6

Bird/Animal proteins
Funghi
Chemicals

Question 7

How can we treat HP?

Answer 7

Avoid the antigen

Corticosteroids (e.g. prednisolone) can help symptoms.

Question 8

How does chronic unstopped HP end?

Answer 8

Fibrosis ending in end-stage honeycomb lung.