Septic arthritis is an intensely painful infection in a joint. The joint can become infected with germs that travel through your bloodstream from another part of your body. Septic arthritis can also occur when a penetrating injury brings germs directly into the joint.
Infants and older adults are most likely to develop septic arthritis. The most common joints affected are the knees and hips. Septic arthritis can quickly and severely damage the cartilage and bone within the joint, so prompt treatment is crucial.
Treatment involves draining the joint with a needle or via an operation. Intravenous antibiotics also may be necessary to stop the infection.
Septic arthritis typically causes extreme discomfort and difficulty using the affected joint. The joint may be swollen, red and warm, and you might have a fever.
When to see a doctor
Septic arthritis can be caused by bacterial, viral or fungal infections. Bacterial infection with Staphylococcus aureus (staph) is the most common cause. Staph commonly lives on even healthy skin.
Septic arthritis may develop when an infection elsewhere in your body, such as an upper respiratory tract infection or urinary tract infection, spreads through your bloodstream to a joint. Less commonly, a puncture wound, drug injection or surgery in or near a joint may give the germs a pathway into the joint space.
The lining of your joints (synovium) has little ability to protect itself from infection. Your body's reaction to the infection — including inflammation that can increase pressure and reduce blood flow within the joint — contributes to the damage.
Risk factors for septic arthritis include:
Having a combination of risk factors usually puts you at a greater risk than having just one risk factor.
If treatment is delayed, septic arthritis can quickly lead to joint degeneration and permanent damage.
Preparing for your appointment
If you have painful and inflamed joints, you're likely to start by seeing your family doctor. He or she may refer you to an infectious disease or joint specialist.
Because appointments can be brief and because there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
List your questions from most important to least important in case time runs out. For septic arthritis, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.
What to expect from your doctor
Tests and diagnosis
The following tests typically help diagnose septic arthritis:
Treatments and drugs
Doctors rely on joint drainage and antibiotic drugs to treat septic arthritis.
Last Updated: 2013-01-17
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