While pleural effusions more commonly arise in patients with hospital-acquired pneumonia, empyemas more commonly develop in patients with community-acquired pneumonia, typically Streptococcus pneumonia, and are commonly associated with alcohol use disorder, gastroesophageal reflux disease (GERD), and diabetes. When an empyema is associated with hospital-acquired pneumonia, it is usually methicillin-resistant Staphylococcus aureus or Pseudomonas, with S aureus being most commonly associated with thoracic surgery.
Diagnosis is made by x-ray, MRI, or CT. Less complex empyemas may be treated with nonsurgical interventions such as thoracentesis or thoracostomy while more complex empyemas with more loculations may require surgical intervention by video-assisted thoracoscopic surgery (VATS) or thoracotomy.
Additional independent risk factors for empyema development are older age or male sex (3:1 ratio in males to females). Of note, about 20% of patients who develop an empyema have diabetes or cancer.
J86.9 – Pyothorax without fistula
58554001 – Empyema of pleura
Differential Diagnosis & Pitfalls
- Pulmonary embolism
- Pleural effusion
- Pneumonia (eg, viral, bacterial)
- Aspiration pneumonia / pneumonitis
- Viral upper respiratory infection
- Autoimmune pleuritis / serositis
- Malignancy (particularly primary lung, mesothelioma, metastasis to lung or pleura)
- Pericardial effusion
- Acute coronary syndrome
- Coronary artery disease
- Musculoskeletal injury
- Toxic inhalation
- Pneumoconiosis (asbestosis, silicosis, etc)
- Sickle cell pain crisis
- Pulmonary edema
- Granulomatosis with polyangiitis
- Langerhans cell histiocytosis
- Goodpasture syndrome