While experts are not sure how many cases of bursitis are septic,1 they do agree that septic bursitis requires prompt antibiotic treatment. Septic bursitis means a bursa is infected, and antibiotics can prevent the infection from spreading into the bloodstream, a condition that can be life-threatening.
It can be frustratingly difficult to distinguish septic bursitis from regular bursitis. Both types of bursitis can cause pain, swelling, and tenderness of the area immediately above the joint. The only way to know if you have septic bursitis is to get a medical diagnosis.
How does a doctor decide if you have septic bursitis?
A diagnosing physician or other licensed medical professional will consider many factors, including these 5 questions:
- Are you showing signs of infection? Extreme warmth or redness of the skin over the bursa, extreme tenderness at the joint, fever or chills, and a general feelings of sickness are more likely to occur if you have septic bursitis.
- What joint is affected? Septic bursitis is most likely to occur in bursae that lie just below the skin, such as the prepatellar bursa at the kneecap and the olecranon bursa at the tip of the elbow. These bursa can be exposed to infectious bacteria after a cut, scrape, or bug bite.
- What do you do for work and hobbies? People who spend time on their knees and elbows, such as gardeners, carpenters, and athletes, are at a higher risk for septic bursitis.2
- What is your medical history? If you take a corticosteroid or another medication that weakens your immune system, or if you have a condition like cancer, HIV, or diabetes, you are at a greater risk for septic bursitis.2 You are also at a higher risk if you have a skin infection or a recent history of septic arthritis or tuberculosis.
- What do the lab tests suggest? If a medical professional suspects you may have septic bursitis, they will probably order blood tests or analyses of the fluid inside the bursa. (A bursa fluid analysis will require removing fluid from the affected bursa with a needle and syringe. This procedure is called bursal aspiration.)
While joint fluid analysis is considered the gold standard for diagnosing septic bursitis, it is not foolproof. Certain infectious microorganisms may not show up in these analyses. If no infection is identified in the joint fluid but other signs strongly point to septic bursitis, a doctor will prescribe antibiotics.
Do you need to take antibiotics for septic bursitis?
If you are diagnosed with septic bursitis, antibiotic treatment will begin as soon as possible. Your doctor may also recommend draining the infected bursa.
If septic bursitis is left untreated, the fluid inside the bursa can turn to pus. In addition, the infection can spread to the bloodstream and other parts of the body. If the infection spreads, symptoms will become worse and the infection can even become life-threatening.
Decrease your risk of chronic septic bursitis
If the infection isn’t fully eliminated, your septic bursitis may return and become chronic. A chronically infected bursa can affect nearby tendons, ligaments, and other surrounding tissues, causing you more pain and other problems in the future.2 For this reason, if you are prescribed antibiotics, take them as directed and for the length of time indicated.
While there is some debate among experts, the minimum treatment for mild cases of septic bursitis is generally considered to be 10 days of antibiotic.2 Longer antibiotic treatment, as well as additional aspiration to drain the bursa fluid, may be necessary until signs of the infection are eliminated.