Infectious arthritis, also called septic arthritis, involves a sudden, severe infection of a joint. It can cause severe pain, swelling, a fever, and tissue damage and needs prompt treatment.
Infectious arthritis usually affects just one joint, but it can spread. As a result, it is essential to diagnose and treat it quickly to prevent severe joint damage and the spread of infection.
This article looks at the symptoms, causes, treatments, and recovery process. It also describes how infectious arthritis differs from reactive arthritis.
Infectious arthritis occurs when bacteria, fungi, or a virus infects a joint, causing inflammation. It can occur suddenly and cause intense pain, fever, and chills.
A person’s immune system regularly removes these harmful pathogens from the body, but when they enter closed areas, such as a joint, they can multiply rapidly and cause severe inflammation and tissue destruction.
Prevalence and impact
Though the name may be misleading, infectious arthritis is not contagious. However, it can be quite serious.
Research shows that illness from septic arthritis occurs in at least one-third of people with the condition. Approximately
Infectious arthritis can impact people from historically marginalized groups more severely, likely a result of disparities in access to and quality of medical care.
The most common cause of septic arthritis or infectious arthritis is bacteria, fungi, or viral bodies that enter the space around a joint.
Bacterial infection is the most common cause of septic arthritis. A 2019 review found that bacteria from the Staphylococci family cause
The bacteria typically reach the joint through the bloodstream.
Undergoing joint replacement surgery or having animal bites, cuts, or puncture wounds on the joints
Having a weakened immune system or a history of other joint problems, such as gout, rheumatoid arthritis, lupus, or osteoarthritis, may also increase the risk as joints that are damaged may be more susceptible to infection.
Septic arthritis causes severe inflammation that can break down tissue in the joint. This may lead to permanent damage to the cartilage and bone.
Like other forms of arthritis, the primary symptoms are swelling, pain, and stiffness in the affected joint. Other septic arthritis signs and symptoms include:
- pain that is more severe than the pain of noninfectious inflammatory arthritis
- a limited range of motion in the affected joint
- redness around the affected joint
- changes in appetite
- increased irritability
- skin rashes
This condition can affect several joints, though septic arthritis in the knee is most common.
Septic arthritis may affect other joints, including:
Symptoms can appear and become severe very soon after the infection develops, sometimes within a few hours. People may also experience other symptoms, depending on the cause of the infection.
Anyone can have infectious arthritis, but certain factors
- existing joint disease, such as rheumatoid arthritis, gout, lupus, or osteoarthritis
- joint damage
- recent joint surgery
- skin infections
- intravenous (IV) drug use
- puncture wounds
- prolonged antibiotic therapy
In addition, anyone who is at risk of contracting bacteria into the joint is at a higher risk of getting the condition. This includes people who have animal bites in the joint, people who have artificial joints, or people undergoing surgery on the joints.
Septic arthritis treatment options can vary depending on which pathogen is causing the condition.
Because the condition can become severe rapidly, doctors
In the first stage of treatment for a bacterial infection, healthcare professionals typically administer antibiotics directly into a person’s bloodstream.
If the antibiotics are effective, the symptoms can improve within 48 hours. However, a person may need IV antibiotics for 2–4 weeks, depending on the severity of the condition. Usually, doctors arrange for people to have IV antibiotics at home.
They may then prescribe oral antibiotics for a further 2–6 weeks.
If a type of fungus is causing the infection, doctors treat it with an antifungal medication instead of antibiotics.
Draining the joint
Doctors may need to drain fluid from an affected joint to help remove the harmful pathogens and inflammatory substances from the body. They can do this with a syringe or with a procedure called arthroscopy. This involves inserting a small drainage tube into the affected joint through a small incision.
People with infectious arthritis may have physical therapy to help reduce symptoms and preserve the joint’s range of motion and function. A doctor may also recommend wearing a splint to support the affected joint.
For anyone wearing a splint, it is essential to do range-of-motion exercises to prevent the joint muscles from shortening. A person should also not wear the splint continuously.
If a person does not receive early, robust treatment, infectious arthritis
The effects of this damage on daily life depend on which joint is involved. For example, damage to a knee joint can affect the ability to stand or walk.
Infectious arthritis may also occur alongside osteomyelitis, which is an infection within a bone.
It is important to have infectious arthritis diagnosed as soon as possible. First, a doctor performs a physical examination and discusses the person’s medical history with them.
This alone does not provide enough information for a doctor to distinguish infectious arthritis from many other inflammatory conditions, so if they suspect infectious arthritis, they will recommend further tests.
These tests may require samples of blood and fluid from the affected joint. A
Doctors may also recommend imaging tests, such as X-rays or MRI scans, to assess the extent of damage that the infection has already caused.
A person may mistake infectious arthritis for reactive arthritis. The two can cause similar symptoms. However, infectious arthritis results from an active infection in the joint, while reactive arthritis usually results from a recent infection elsewhere in the body.
Reactive arthritis does not typically result from an infection spreading into a joint. Instead, it occurs when the immune system overreacts to the initial infection, triggering joint inflammation.
Can septic arthritis spread to other joints?
Infectious arthritis usually affects only one joint. However, it can affect multiple joints in some cases and may spread to other parts of the body if left untreated.
What other organisms can cause septic arthritis?
Although bacteria usually cause septic arthritis, several types of viruses and fungi can also cause an infection.
Rubella, hepatitis B or C, parvovirus, alphavirus, and flavivirus
When does a person need surgery for septic arthritis?
Treatment for infectious arthritis often involves a combination of antibiotics and joint fluid drainage using either a tube or syringe.
In some cases, a doctor may also recommend surgery to drain the joint, although this
Infectious arthritis is a severe condition that can cause permanent bone and tissue damage. Bacterial infections are the
A person with infectious arthritis may experience sudden swelling, severe pain, dizziness, and fatigue.
Early and aggressive treatment, including IV antibiotics, can significantly improve a person’s septic arthritis outlook. If treatment begins in time, a person may make a full recovery without any lasting damage.