Septic bursitis (infectious bursitis) is an infection of the bursae, the small sacs of fluid that cushion and lubricate an area where tissues—including bone, tendon, ligament, muscle, or skin—rub against one another. Common sites of septic bursitis are the tips of the elbows and the kneecaps.

It may be hard to tell the difference between inflammation in a bursa (bursitis) and infection in a bursa (septic bursitis). Symptoms of septic bursitis may include:

• Pain, swelling, redness, and warmth in the area of the infected bursa.
• Fever.
• Swollen glands near the infected bursa.

Antibiotics and drainage (either drainage with a needle or, sometimes, surgical drainage) are required to treat the infection. Sometimes this requires a hospital stay for intravenous (IV) antibiotic therapy or surgery.