II. Definition
- Chronic, nonmalignant, noninfectious diseases
- Lower respiratory tract disease
- Distal lung parenchyma disease
- Alveolar wall inflammation and derangement
III. Causes (Mnemonic: DISCO)
- Drugs (See below)
- Idiopathic Pulmonary Fibrosis
- Sarcoidosis
- Collagen Vascular Disease
- Occupational Exposure
- Asbestos
- Fumes and gasses
IV. Causes: Non-Granulomatous Causes
- Occupational Exposure
- Medications
- Antibiotics (e.g. Nitrofurantoin and GFR<30 ml/min)
- Chemotherapeutics (e.g. Methotrexate)
- Radiation
- Aspiration Pneumonia
- Post ARDS changes
- Idiopathic Pulmonary Fibrosis
- Collagen Vascular Disease
- Goodpasture's Syndrome
- Eosinophilic Pneumonia
- Amyloidosis
- Graft Versus Host Disease (Bone Marrow Transplant)
V. Causes: Granulomatous Causes
- Hypersensitivity Pneumonitis (Organic dust)
- Inorganic dust (Beryllium silica)
- Sarcoidosis
- Langerhans Cell Granulomatosis
-
Granulomatous Vasculitis
- Granulomatosis with Polyangiitis (previously known as Wegener's Granulomatosis)
- Allergic Granulomatosis of Churg-Strauss
- Lymphomatoid Granulomatosis
- Bronchocentric Granulomatosis
VI. Epidemiology: Demographic Breakdown
- Age 20 to 40 years
- Sarcoidosis
- Collagen Vascular Disease
- Eosinophilic Granuloma or Pulmonary Histiocytosis X
- Lymphangioleiomyomatosis
- Age over 40 years
- Female Predominance
- Male Predominance
- Pneumoconiosis (Asbestosis)
- Tobacco exposure
VII. Symptoms
- Historical data
- Complete occupational and environmental exposures
- Complete medication history
- Exertional Dyspnea
- Chronic Dyspnea
- Fatigue
- Malaise
VIII. Signs
- Inspiratory crackles (rales) at posterior lung bases
- Pulmonary Hypertension
-
Fingernail
Clubbing
- Suggests Idiopathic Pulmonary Fibrosis
- May suggest Bronchogenic Carcinoma
IX. Labs
- ACE Level is non-specific and not useful
-
Erythrocyte Sedimentation Rate (ESR)
- Increased
-
Complete Blood Count (CBC)
- Polycythemia (rare)
- Arterial Blood Gas (ABG)
X. Diagnosis
-
Pulmonary Function Tests
- Restrictive pattern
- Reduced Total Lung Capacity
- DLCO decreased
- Bronchoalveolar Lavage
- Alveolar cells reflect type of inflammation
XI. Radiology
-
Chest XRay
- Lung parenchymal change (90%)
- Increased Interstitial Markings
- Non-resolving infiltrates
- Gallium Lung scanning
- Diffuse inflammation