Infectious Arthritis - Know the Warning Signs

Bacteria, Virus, or Fungus Can Cause Infectious Arthritis

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What Is Infectious Arthritis?

Infectious arthritis is caused by a germ that travels through the body to a joint. The germ can be a bacterium, virus, or fungus. The germ can enter the body through the skin, nose, throat, ears, or through an open wound. Most often, infectious arthritis develops after an already existing infection travels through the body to a joint.

Who Develops Infectious Arthritis?

Anyone can develop infectious arthritis but people with chronic conditions that make it hard to fight off infection are more susceptible.

People who have pre-existing arthritis are also more prone to developing infectious arthritis because:

  • germs target damaged joints as opposed to healthy joints
  • infection is also a possible complication following joint replacement surgery
  • certain medications that suppress the immune system, such as DMARDs or biologics, increase the risk of infection

Warning Signs for Infectious Arthritis

It's important to know the warning signs for infectious arthritis so that treatment can begin quickly. The warning signs are slightly different, depending on whether the causative agent (germ) is a bacterium, virus or fungus.

If caused by bacteria, warnings signs include:

  • pain and swelling is very localized (generally, in one particular area of the body)
  • symptoms develop suddenly
  • fever
  • chills

If caused by a virus, warnings signs include:

  • pain that is described as "all-over," not localized
  • no fever, usually

If caused by a fungus, warnings signs include:

  • pain and swelling develop slowly, over an extended period of time
  • pain and swelling may be all-over or localized
  • mild fever

Bottom Line: Get Treatment Promptly

Infectious arthritis is not typically a chronic condition. With prompt and accurate treatment, infectious arthritis usually resolves. With delayed treatment or no treatment, joint damage may become permanent and the infection can spread to other body parts.

A correct diagnosis is important so proper treatment can begin. Knowing what the warning signs are -- and recognizing those signs when they occur -- allow you to seek medical treatment immediately and that is the best chance for full recovery from infectious arthritis.


Infectious Disorders. Septic Arthritis. Primer on the Rheumatic Diseases. Arthritis Foundation. Edition 12.

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