Hypersensitivity Pneumonitis

Question 1

Hypersensitivity Pneumonitis: Define

Answer 1

Hypersensitivity Pneumonitis is inflammation of the alveoli within the lung caused by hypersensitivity to inhaled organic dust, fungus, moulds, or chemcials.
Sufferers are commonly exposed to the dust by their occupation or hobbies.

Question 2

Hypersensitivity Pneumonitis: Causes

Answer 2

Bird/Pigeon-facnier’s lung
Farmer’s lung
Malt Workers lung
Sugar Workers lung

Question 3

Hypersensitivity Pneumonitis: Symptoms and Signs

Acute

Answer 3

Acute Phase: the alveoli are infiltrated with acute inflammatory cells. 
Acute Presentation: 4-6 hours post-exposure)
Crackles 
Chills
Cough - dry
Breathlessness
Myalgia 
Wheeze
Fever
Tachypnoea

Question 4

Hypersensitivity Pneumonitis: Symptoms and Signs

Chronic

Answer 4

In the chronic phase there is granuloma formation and  obliterative bronchiolitis
Chronic Presentation: 
Crackles 
Cough
Breathlessness - progressive/exertional
Malaise
Wheeze

Question 5

Hypersensitivity Pneumonitis: Investigations

Answer 5

Bloods - FBC, ESR, ABGs
CXR - upper-zone consolidation, hilar lymphadenopathy, honeycomb lung
Lung Function Test
Bronchoalveolar Lavage (BAL) fluid - shows increased lymphocytes and mast cells.

Question 6

Hypersensitivity Pneumonitis: Treatment

Answer 6

Avoid dust - if dust is cause

Steroids - anti-inflammatory