Pneumonia

Pneumonia is a general term in widespread use, defined as infection within the lung. It is due to material, usually purulent, filling the alveoli.

Terminology

Pneumonia is in contrast to pneumonitis, which is inflammation of the pulmonary interstitium. Of note, some of the interstitial lung diseases are termed pneumonia rather than pneumonitis. The term consolidation is often erroneously used as a synonym for pneumonia.

Classification

Pneumonias can be classified by:

• etiology
  • infective agent
    • bacterial (pyogenic) pneumonia
      • cavitating bacterial pneumonia
    • fungal pneumonia
      • pneumocystis pneumonia (PCP)
    • mycobacterial pneumonia
    • viral pneumonia
      • coronavirus
        • COVID-19
        • Middle East respiratory syndrome (MERS) infection
        • severe acute respiratory syndrome (SARS)
      • varicella pneumonia
  • setting of infection
    • community-acquired pneumonia
    • hospital-acquired pneumonia (HAP)
      • ventilator-associated pneumonia (VAP)
      • healthcare-acquired pneumonia (HCAP)
    • aspiration pneumonia
  • lipid: lipoid pneumonia
• method of spread (a pathological description)
  • bronchopneumonia
  • lobar pneumonia
    • multilobar pneumonia
• radiographic appearance
  • atypical pneumonia
  • round pneumonia
  • cavitating pneumonia
  • hemorrhagic pneumonia

See also

• consolidation
• lobar consolidation