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 called gonococcal arthritis.
Bacterial arthritis; Non-gonococcal bacterial 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 bacterium.
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.
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 and irrigate (wash) the joint.
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.
Cook PP, Siraj DS. Bacterial arthritis. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelly and Firestein's Textbook of Rheumatology. 10th ed. Philadelphia, PA: Elsevier; 2017:chap 109.
Robinette E, Shah SS. Septic arthritis. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 705.