Respiratory function tests were severely reduced as was his exercise tolerance.
Bronchoscopy and washing showed a lymphocytosis of 80%, the majority of the lymphocytes were T8, this is diagnostic of SAHP.
A follow-up CT after 19 days and a repeated lung function tests revealed a significant improvement.
The differential diagnosis here lies between:
The high lymphocyte count and a definite history of antigen exposure plus the response to removal from birds make SAHP the most likely diagnosis.
On HRCT, subacute hypersensitivity pneumonitis usually has the following features:
- ground-glass opacity
- centrilobular nodules
- mosaic attenuation
- expiratory air trapping
- mediastinal lymphadenopathy in about 50%