(Bacterial Arthritis; Infectious Arthritis; Pyogenic Arthritis)
Septic arthritis is a serious infection of the joints caused by bacteria. This infection causes the joint to be filled with pus cells. These pus cells release substances directed against the bacteria. However, this action can damage the joint structures, bone, and surrounding cartilage.
Septic arthritis develops when bacteria spreads from the source of infection through the bloodstream to a joint. It can result from:
- Infection due to an injection
- Other infections
Septic arthritis can also be caused from injury or trauma. It can result from:
- A penetration wound
- An injury that affects the joint
- Joint surgery/replacement
Septic arthritis can occur at any age, but it generally affects children aged 3 years old and younger. In infants, the hip is a frequent site of infection. In toddlers, it is the shoulders, knees, and hips.
Septic arthritis rarely occurs from early childhood through adolescence. After that, it occurs more often. In adults, it most commonly affects weight-bearing joints, such as the knees.
Joint Damage in Knee
Factors that may increase your chance of developing septic arthritis include:
- Diseases that weaken the immune system, such as HIV or taking drugs that suppress immunity
- A history of joint problems or having other types of arthritis, gout, or systemic lupus erythematosus
- A history of IV drug use
- Chronic illnesses, such as anemia, diabetes, sickle cell, and kidney failure
- Joint replacement or organ transplant surgery
- Recent joint injections, such as cortisone or hyaluronic acid
- Alcohol use disorder
- Skin conditions, such as psoriasis and eczema
Symptoms may include:
Newborn or infants:
- Crying when a joint is moved, such as during a diaper change
- Inability to move the limb of a joint
- Swelling and redness
- Persistent crying for any reason
Children and adults:
- Intense joint pain
- Joint swelling and redness
- Inability to move a joint or its limb
You will be asked about you or your child’s symptoms and medical history. A physical exam will be done. Your doctor may refer you to a specialist.
Bodily fluids may need to be tested. This can be done with:
- Testing joint fluids
- Blood tests
Images may be taken of your bodily structures. This can be done with:
Antibiotic therapy is started as soon as a diagnosis is made. In the beginning, antibiotics are given by IV. This is to ensure that the infected joint receives medication to kill the bacteria. The specific medications used depend on the type of bacteria that is causing the infection. The remaining course of antibiotics may be given by mouth.
Fluid may be removed from the joint to reduce the likelihood of joint damage. This may be done either by placing a needle in the joint or through surgery.
Rest, preventing the joint from moving, and warm compresses may be used to manage pain. Physical therapy or exercises may also speed recovery.
To help reduce your chance of getting septic arthritis, get prompt treatment of infections that could lead to septic arthritis.
National Institute of Arthritis and Musculoskeletal and Skin Diseases
The Arthritis Society
Ernst AA, Weiss SJ, Tracy LA, Weiss NR. Usefulness of CRP and ESR in predicting septic joints. South Med J. 2010;103(6):522-526.
Howard A, Wilson M. Septic arthritis in children. BMJ. 2010;341:c4407.
Ma L, Cranney A, Holroyd-Leduc JM. Acute monoarthritis: what is the cause of my patient's painful swollen joint? CMAJ. 2009;180(1):59-65.
Septic arthritis. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116123/Septic-arthritis. Updated July 9, 2015. Accessed September 27, 2016.
Septic arthritis. Patient UK website. Available at http://patient.info/health/septic-arthritis-leaflet. Updated August 30, 2013. Accessed June 29, 2015.
Last reviewed May 2016 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.