1. Esam H. Alhamad, M.D Assistant Professor of Medicine Consultant Pulmonary & Critical Care Medicine

2. ATS/ERS. Am J Respir Crit Care Med 2002;165:277-3

3. INTERSTITIAL LUNG DISEASE Hypersensitivity Pneumonia Idiopathic pulmonary Fibrosis Smoking Associated ILD

4. Hypersensitivity Pneumonia Antigens Mammalian and avian protein Fungi Thermophilic bacteria Certain small molecular weight compounds

5. CLINCAL FORMS ACUTE SUBACUTE CHRONIC

6. ACUTE FORM Symptoms appear 4-8 hour after exposure Fever, chills, malaise, tightness of the chest cough, dyspnea, expectoration, headache Symptoms gradually decrease over the next 24-48 hours, but recur after next exposure

7. SUBACUTE/CHRONIC FORMS Continuous low-level antigen exposure (e.g few birds at home) Insidious onset of the disease Duration of symptoms 2-24 months

8. SUBACUTE/CHRONIC FORMS Chronic progressive dyspnea Fatigue, poor appetite, weight loss Cough with mucoid sputum Occasional digital clubbing May progress to fibrosis, respiratory failure, cor pulmonale

9. CHEST X-RAY & HRCT Ground glass opacities Poorly defined micronodules Patchy air space opacification Fine and coarse reticular opacities Honeycombing ( chronic advanced cases)

12. PULMONARY FUNCTION TESTS Restrictive, obstructive, or mixed defect Most common finding  Dlco 40% airflow obstruction Emphysema more common than fibrosis Alhamad et al. Clin Chest Med 2001; 22:715-750

13. BRONCHOALVEOLR LAVAGE  T lymphocytes ~ 50%  CD8+ T-cells  CD4+ T-cells  CD4+/CD8+ ratio  CD4+/ CD8+ ratio

14. LUNG BIOPSY Lymphocytes infiltration Granuloma Bronchiolitis Emphysema Fibrosis

16. DIAGNOSIS Clinical, radiologic and functional abnormalities suggestive of an I.L.D History of exposure to HP antigens Positive specific antibodies Lung biopsy Hypersensitivity pneumonitis

17. THERAPY Avoidance of antigen exposure Corticosteroids