Pleural WBC Count >10k

• Parapneumonic Effusion/Empyema (see [[Pleural Effusion-Parapneumonic]]): most common etiology of WBC >10k
• Acute Pancreatitis (see [[Acute Pancreatitis]])
• Acute PE (see [[Acute PE]])
• Collagen Vascular Disease
• Malignancy
• Tuberculosis (see [[Tuberculosis]])

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Neutrophil-Predominant Pleural Effusion

• Parapneumonic Effusion/Empyema (see [[Pleural Effusion-Parapneumonic]])
• Benign Asbestos Pleural Effusion (see [[Benign Asbestos Pleural Effusion]])
• Paragonimiasis (see [[Paragonimiasis]])

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Lymphocyte-Predominant Pleural Effusion

• Tuberculosis (see [[Tuberculosis]])
• Coccidioidomycosis (see [[Coccidioidomycosis]])

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Pleural Fluid Eosinophilia

(defined as pleural eosinophils 10% or greater)
(number of eosinophils in pleural space is closely correlated with pleural IL-5 levels)

• Blood: common etiology
  • Hemothorax (see [[Pleural Effusion-Hemothorax]]): pleural fluid eosinophilia typically appears later, during second week
  • Benign Asbestos Pleural Effusion (see [[Benign Asbestos Pleural Effusion]]): pleural eosinophilia is seen in 50% of cases
  • Acute PE (see [[Acute PE]]): typically when pleural fluid is bloody
• Air: common etiology
  • Pneumothorax (see [[Pneumothorax]]): pleural eosinophils appear within 3 days and peak at day 6
• Parasitic Infection:
  • Paragonimiasis (see [[Paragonimiasis]]): with accompanying PMN-predominance
  • Echinococcosis (see [[Echinococcosis]])
• Drug-Induced Pleural Effusion:
  • Dantrolene (see [[Dantrolene]])
  • Isotretinoin (Accutane) (see [[Isotretinoin]])
  • Mesalamine (see [[Mesalamine]])
  • Nitrofurantoin (see [[Nitrofurantoin]])
  • Penicillins (see [[Penicillins]])
  • Propylthiouracil (PTU) (see [[Propylthiouracil]])
  • Sulfasalazine (see [[Sulfasalazine]])
• Pulmonary Infiltrates with Eosinophilia:
  • Hypereosinophilic Syndrome (see [[Hypereosinophilic Syndrome]])
  • Churg-Strauss Syndrome (see [[Churg-Strauss Syndrome]])
  • Acute Eosinophilic Pneumonia (see [[Acute Eosinophilic Pneumonia]])
• Other
  • Tuberculous Pleuritis (see [[Tuberculosis]]): with accompanying lymphocyte-predominance
  • Idiopathic Pleural Eosinophilia
  • Malignancy: occasionally associated with pleural eosinophilia
  • Parapneumonic Effusion (see [[Pleural Effusion-Parapneumonic]]): occasionally associated with pleural eosinophilia
  • Transudative Pleural Effusion (see [[Pleural Effusion-Transudate]]): some cases have been reported to be associated with pleural eosinophilia