Hypersensitivity pneumonitis
Contents
Etiology
- Immunologic response to inhaled antigen (mold, animal protein and etc.)
Clinical presentation
| Acute | Chronic |
|---|---|
| Abrupt-onset fever, chills, cough, dyspnea, fatigue, leukocytosis | Progressive cough, dyspnea, fatigue, weight loss |
| Episodes often recurrent & self-resolving | Hypoxemia that worsens with exertion |
| Chest x-ray: diffuse reticular interstitial opacities (interstitial fibrosis) |
Diagnosis
- Pulmonary Functional Testing (PFT): restrictive pattern
- Bronchoalveolar lavage (BAL): high relative lymphocyte count
- Lung biopsy: lymphocytic infiltrate, poorly formed noncaseating granulomas, interstitial fibrosis (chronic only)