Risk factors for septic arthritis include:

  • Existing joint problems. Chronic diseases and conditions that affect your joints — such as osteoarthritis, gout, rheumatoid arthritis or lupus — may increase your risk of septic arthritis. An artificial joint, previous joint surgery and joint injury also increase your risk.
  • Taking medications for rheumatoid arthritis. People with rheumatoid arthritis have a further increase in risk because of the medications they take. Rheumatoid arthritis medications may suppress the immune system, making infections more likely to occur. Also, diagnosing septic arthritis in people with rheumatoid arthritis is difficult because many of the signs and symptoms are similar.
  • Skin fragility. If your skin breaks easily and heals poorly, bacteria may have constant access to your body. Skin conditions such as psoriasis and eczema increase your risk of septic arthritis, as do infected skin wounds. People who regularly inject drugs also have a higher risk of infection at the site of injection.
  • Weak immune system. A weak immune system may give you a higher risk of septic arthritis because your body can't defend itself against infections. People with diabetes, kidney and liver problems, and those taking drugs that suppress their immune system have an increased risk of infections.

Having a combination of risk factors usually puts you at a greater risk than having just one risk factor.

Jan. 17, 2013