ILD

Interstitial Lung Disease

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Interstitial Lung Disease

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