Extrinsic Allergic Alveolitis

Question 1

What is EAA.

Answer 1

In sensitized individuals, inhalation of allergens (fungal spores or avian proteins) provokes a hypersensitivity reaction.

Question 2

What occurs in the acute phase of EAA.

Answer 2

The alveoli are infiltrated with acute inflammatory cells.

Question 3

What occurs in chronic exposure to allergens in EAA. (2)

Answer 3

Granuloma formation.

Obliterative bronchiolitis.

Question 4

What are some causes of EAA. (4)

Answer 4

Bird-fanciers and pigeon-fancier’s lung (proteins in bird droppings).
Farmer’s and mushroom worker’s lung (micropolyspora faenia, thermoactinomyces vulgaris).
Malt worker’s lung (aspergillus clavatus).
Bagassosis or sugar worker’s lung (thernmoactinomyces sacchari).

Question 5

What are the clinical features of EAA (acute). (6)

Answer 5

4-6h post exposure:
Fever. 
Rigors. 
Myalgia. 
Dry cough. 
Dyspnoea. 
Crackles (no wheeze).

Question 6

What are the clinical features of EAA (chronic). (5)

Answer 6

Increasing dyspnoea. 
Weight loss. 
Exertional dyspnoea. 
Type 1 respiratory failure. 
Cor pulmonale.