Septic (Infectious) Arthritis | Diagnosis & Treatments

How does a doctor know my child has septic arthritis?

Prompt diagnosis of septic arthritis is necessary to prevent permanent damage to the joint.

In addition to a complete medical history and physical examination, diagnostic procedures for septic arthritis may include:

  • removal of joint fluid: to examine for white blood cells and bacteria
  • blood tests: to detect bacteria
  • phlegm, spinal fluid, and urine tests: to detect bacteria and find the source of infection
  • x-ray: a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film
  • bone scan: a nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; to determine the cause of bone pain or inflammation
  • magnetic resonance imaging (MRI): a diagnostic procedure that uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within the body.
  • radionuclide scans: nuclear scans of various organs to determine blood flow to the organs

Treating septic arthritis

Specific treatment for septic arthritis will be determined by your child's physician based on:

  • your child's overall health and medical history
  • extent of the condition
  • your child's tolerance for specific medications, procedures, and therapies
  • expectation for the course of the disease
  • your opinion or preference

Septic arthritis caused by bacteria usually requires immediate treatment with antibiotics, which can improve symptoms within 48 hours. However, certain infections caused by fungi need treatment with anti-fungal medications, while viral infections usually have to run their course without treatment. To prevent accumulation of pus from the infection, which can damage the joint, pus may be drained with a needle, tube, or surgery. Other treatment may include:

  • medications (for pain and fever)
  • physical therapy (to maintain muscle strength)
  • splinting the joint (to relieve pain)