Extrinsic Allergic Alveolitis

Question 1

What is extrinsic allergic alveolitis

Answer 1

Repetitive allergen inhalation provokes a hypersensitivity reaction where alveoli infiltrated with acute inflammatory cells

Question 2

Extrinsic allergic alveolitis causes

Answer 2

Bird/pigeon-fancier’s lung (bird poo protein)
Farmer’s/mushroom worker’s lung
Malt worker’s lung (Aspergillus clavatus)
Bagassosis/ sugar-worker’s lung (Thermoactinomyces sacchari)

Question 3

Extrinsic allergic alveolitis acute presentation

Answer 3

Fever, rigors
Myalgia
Dry cough
Dyspnoea
Fine bibasal crackles

Question 4

Extrinsic allergic alveolitis chronic presentation

Answer 4

Clubbing (50%)
Increasing/exertional dyspnoea
Weight loss
Type I resp failure
Cor pulmonale

Question 5

Extrinsic allergic alveolitis investigations acute

Answer 5

Neutrophilia, raised ESR
CXR shows upper-zone mottling/consolidation
Lung FTs show reversible restrictive defect

Question 6

Extrinsic allergic alveolitis investigations chronic

Answer 6

CXR shows upper-zone fibrosis + honeycomb lung
CT chest shows ground-glass appearance with extensive fibrosis
LungFTs show restrictive defect

Question 7

Extrinsic allergic alveolitis management acute

Answer 7

Remove allergen
Give O2 (35-60%)
PO pred 40mg/d

Question 8

Extrinsic allergic alveolitis management chronic

Answer 8

Allergen avoidance
Facemask
Long-term steroids often show improvement