Empyema

An empyema (from Greek ἐμπύημα, "abscess") is a collection or gathering of pus within a naturally existing anatomical cavity. For example, pleural empyema is empyema of the pleural cavity. It must be differentiated from an abscess, which is a collection of pus in a newly formed cavity.

Classification

In human medicine, empyema occurs in:

• the pleural cavity (pleural empyema also known as pyothorax)
• the thoracic cavity
• the uterus (pyometra)
• the appendix (appendicitis)
• the meninges (subdural empyema)
• the joints (septic arthritis)
• the gallbladder