Septic Arthritis (Infectious Arthritis) in Children
Septic arthritis is an infection in the joint fluid (synovial fluid) and joint tissues.
It occurs more often in children than in adults. The infection usually reaches the
joints through the bloodstream. In some cases, joints may become infected because
injection, surgery, or injury.
Different types of bacteria, viruses, and fungi can infect a joint. The common types
that can cause septic arthritis include:
Staphylococcus aureus. These are common bacteria that often cause skin
Haemophilus influenzae. These are bacteria that can infect the larynx, trachea, and bronchi.
Gram-negative bacilli. This is a group of bacteria that includes Escherichia
coli (E. coli).
Streptococci. This is a group of strep bacteria that can lead to many
most common type of bacteria that cause septic arthritis is Staphylococcus aureus,
staph. It is also known as S. aureus. These bacteria can enter the body in many ways,
- An infection that spreads from another place on the body, such as the skin or genitals
- An infected wound
- A broken bone that goes through the skin (open fracture)
- Foreign object that goes through the skin
- Injury that breaks the skin
Septic arthritis may occur without any known risk factors. But children who have an
open skin wound and a weakened immune system may be at greater risk. A weakened immune
system can be caused by diabetes, kidney disease, HIV infection, or cancer.
most common joints affected by septic arthritis are the knee, hip, shoulder, elbow,
wrist. Most often, only 1 joint is affected. Symptoms may vary in each child. Common
- Joint pain, often severe
- Joint swelling
- Redness in the affected area
around the affected area
- Limited use of the affected limb, such as not wanting to walk
- Guarding or protecting the affected area to keep it from being touched or seen
- Other symptoms of illness, such as vomiting, sore throat, or headache
- Being grouchy (irritable)
- Loss of appetite
These symptoms can seem like other health conditions. Make sure your child sees a
healthcare provider for a diagnosis.
Early diagnosis of septic arthritis is important. It can prevent long-term (permanent)
damage to the joint. Your child’s healthcare provider will ask about your child’s
history and give your child a physical exam. Tests may also be done, such as:
This is done to check for white blood cells and bacteria in the
Blood tests. These are done to look for bacteria.
Phlegm, spinal fluid, and urine tests. These are done to look for bacteria and find the source of infection.
X-ray. This test uses a small amount of radiation to make images of internal tissues, bones,
Bone scan. This imaging test uses a tiny amount of a radioactive substance to look for arthritis
changes in the joints.
This test uses large magnets and a computer to make detailed images of organs and
other tissues without using X-rays.
Radionuclide scans. These scans use a tiny amount of a radioactive substance to look at organs and the
blood flow to them.
Treatment will depend on your child’s symptoms, age, and general
health. It will also depend on how severe the condition is.
Septic arthritis often needs treatment right away with antibiotics if bacteria are
source of infection. This can improve symptoms within 48 hours. Some infections caused
by fungi need treatment with antifungal medicine. Viral infections are not treated
may be drained from the joint. Pus buildup can damage the joint. The pus is drained
a needle, tube, or surgery. Other treatment may include:
- Medicines for pain and fever
therapy to keep muscle strength
splint on the joint to ease pain
Septic arthritis can cause joint damage. If your child’s growth plate was affected,
this may cause an arm or leg to not grow to the full adult length. The growth plate
the part of the bone where new bone is created. This area of the bone helps determine
its final adult length. Make sure to follow up with your child's healthcare provider
prevent long-term problems.
When to Call a Healthcare Provider
the healthcare provider if your child’s symptoms get worse or about any new
- Septic arthritis is an infection in the joint fluid (synovial fluid) and joint tissues.
It occurs more often in children than adults.
- Different types of bacteria, viruses, and fungi can infect a joint.
- Symptoms include fever, joint pain, swelling, redness, and warmth.
treatment with antibiotics if bacteria are the source of infection is needed to stop
the risk for joint damage.
- Other treatments include medicines for pain and fever, draining the joint, physical
therapy, and splints.
Tips to help you get the most from a visit to your child’s healthcare provider:
- Know the reason for the visit and what you want to happen.
- Before your visit, write down questions you want answered.
- At the
visit, write down the name of a new diagnosis and any new medicines, treatments, or
tests. Also write down any new instructions your provider gives you for your
- Know why
a new medicine or treatment is prescribed and how it will help your child. Also know
what the side effects are.
- Ask if your child’s condition can be treated in other ways.
- Know why a test or procedure is recommended and what the results could mean.
- Know what to expect if your child does not take the medicine or have the test or procedure.
- If your child has a follow-up appointment, write down the date, time, and purpose
for that visit.
- Know how you can contact your child’s provider after office hours. This is important
if your child becomes ill and you have questions or need advice.