Septic arthritis is inflammation of a joint due to a bacterial or fungal infection. Septic arthritis that is due to the bacteria that cause gonorrhea has different symptoms and is also called gonococcal arthritis.
Septic arthritis develops when bacteria or other tiny disease-causing organisms (microorganisms) spread through the blood to a joint. It may also occur when the joint is directly infected with a microorganism from an injury or during surgery. Joints that are commonly affected are the knee and hip.
Most cases of acute septic arthritis are caused by staphylococcus or streptococcus bacteria.
Chronic septic arthritis (which is less common) is caused by organisms including Mycobacterium tuberculosis and Candida albicans.
The following conditions increase your risk for septic arthritis:
Septic arthritis may be seen at any age. In children, it occurs most often in those younger than 3 years. The hip is often the site of infection in infants. Most cases are caused by the bacteria group B streptococcus. Another common cause is Haemophilus influenza, especially if the child has not been vaccinated for this bacteria.
Symptoms usually come on quickly. There is a fever and joint swelling that is usually in just one joint. There is also intense joint pain, which gets worse with movement.
Symptoms in newborns or infants:
Symptoms in children and adults:
Chills may occur, but are uncommon.
The health care provider will examine the joint and ask about the symptoms.
Tests that may be done include:
Antibiotics are used to treat the infection.
Resting, raising the joint above heart level, and using cool compresses may help relieve pain. After the joint starts to heal, exercising it can help speed recovery.
If joint (synovial) fluid builds up quickly due to the infection, a needle may be inserted into the joint to withdraw (aspirate) the fluid. Severe cases may need surgery to drain the infected joint fluid.
Recovery is good with prompt antibiotic treatment. If treatment is delayed, permanent joint damage may result.
Call for an appointment with your provider if you develop symptoms of septic arthritis.
Preventive (prophylactic) antibiotics may be helpful for people at high risk.
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.