Key Features of Extrinsic Allergic Alveolitis (EAA):
Occupational Exposure: Inhalation of organic particles, such as avian proteins, fungal spores, and thermophilic actinomycetes.
1. Farmer’s lung: Spores of Saccharopolyspora rectivirgula.
Symptoms:
. Acute: Shortness of breath, dry cough, and sometimes fever, occurring 4-8 hours after exposure.
. Chronic: Persistent cough and progressive dyspnoea.
Physical Examination:
Diffuse fine crackles on auscultation.
Imaging:
. Chest X-ray: Diffuse micronodular interstitial shadowing, particularly in the upper and mid-zones.
Laboratory Tests:
i. Bronchoalveolar lavage: Lymphocytosis.
ii. Blood tests: Typically, no eosinophilia.