Hypersensitivity pneumonitis (Extrinsic allergic alveolitis) Flashcards
What is another name for hypersensitivity pneumonitis?
Extrinsic allergic alveolitis
What is hypersensitivity pneumonitis?
Hypersensitivity induced lung damage due to a variety of inhaled organic particles
What is hypersensitivity pneumonitis mainly due to?
Immune-complex mediated tissue damage (type III hypersensitivity)
What type of reaction is hypersensitivity pneumonitis?
Widespread inflammatory reaction
What are the main causes of hypersensitivity pneumonitis?
Bird fanciers’ lung
Farmers lung
Malt workers’ lung
Mushroom workers’ lung
What is the cause of bird fancier’s lung?
Avian proteins from bird droppings
What is the main cause of farmers’ lung?
Spores of Saccharopolyspora rectivirgula from wet hay
What is the cause of malt workers’ lung?
Aspergillus clavatus
What is the main cause of Mushroom workers’ lung?
Thermophilic actinomycetes
What are the phases of hypersensitivity pneumonitis?
Acute and Chronic
When does the acute phase of extrinsic allergic alveolitis occur?
4- 8 hours post exposure
How does the acute phase of hypersensitivity pneumonitis present?
dyspnoea
dry cough
fever
How does the chronic phase of extrinsic allergic alveolitis present?
lethargy
dyspnoea
productive cough
anorexia and weight loss
When does the chronic phase of extrinsic allergic alveolitis occur?
Weeks to months post exposure
How would you diagnose hypersensitivity pneumonitis?
Chest x-ray