Sign up for email updates


Back Pain & Osteoporosis
Coronary Heart Disease
Depression & Anxiety
Digestive Disorders
Heart Attack Prevention
Hypertension & Stroke
Lung Disorders
Nutrition & Weight Control
Prostate Disorders



Infectious Arthritis


A painful, red, warm, swollen, and stiff joint. (In some cases, multiple joints are affected.)

Fever (possibly as high as 104°F) and chills.


Skin rash (with Lyme arthritis, as well as gonorrheal, syphilitic, and some varieties of viral arthritis).

When To Call Your Doctor

Call a doctor immediately if you develop symptoms of infectious arthritis. Prompt treatment may help prevent permanent damage to the joint.

Consult your doctor immediately if you have rheumatoid arthritis or gout and you develop arthritic symptoms that do not respond to the medication prescribed for flare-ups.

What Is It?

Infectious arthritis is joint inflammation due to infection by one of a number of microorganisms. The infectious organism may enter the joint directly from a wound, or the infection may spread from a nearby site (such as a boil), but most often it travels to the joint via the bloodstream from an infection elsewhere in the body. The knee and other weight-bearing joints are the ones most commonly affected.

Infectious arthritis is not a permanent condition and does not lead to other forms of joint inflammation, such as osteoarthritis or rheumatoid arthritis. However, if left untreated, it may cause lasting stiffness and limitation of movement in the affected joint or joints.

What Causes It?

A bacterial infection in another part of the body may invade a joint (usually only one) and result in infectious arthritis, typically accompanied by severe joint pain and swelling, fever, and a general feeling of illness. Staphylococcus, the strain of bacteria that causes skin infections (boils), is the most common underlying cause, but various other strains may produce infectious arthritis too, including those that cause strep throat, gonorrhea, and tuberculosis. Most cases of bacterial arthritis tend to be acute but relatively short-lived, except for those associated with tuberculosis, which tend to be more mild and progress gradually over a period of months.

Gonococcal bacterial arthritis affects people who do not have a previously damaged joint or bloodstream infection. The gonococcal organism is the most common cause of infectious arthritis among sexually active young women and men. It is rare after age 45. Unlike the other types of bacterial arthritis, it may affect several joints at once, especially those in the hands and wrists.

Nongonococcal bacterial arthritis affects patients with specific risk factors—including abnormal joint anatomy (such as in rheumatoid arthritis), previous joint trauma or surgery, advanced age, diabetes, corticosteroid or other immunosuppressive use, and endocarditis (infection of the inner lining of the heart).

Viral infection, including the viruses that cause hepatitis B, rubella, mumps, infectious mononucleosis, and herpes, may cause infectious arthritis. In some cases, the rubella vaccine may be a cause as well. Viral arthritis often affects multiple joints but generally leaves no permanent damage.

Fungal infection may cause infectious arthritis; it typically progresses more slowly and is milder than bacterial arthritis.

Lyme disease, transmitted by a tick bite, may cause recurrent bouts of infectious arthritis (Lyme arthritis) despite initial treatment.

Syphilis may cause infectious arthritis, although this is now quite rare.


Obtain prompt treatment for infections elsewhere in the body.


Patient history and physical examination.

Fluid culture from the swollen joint. Fluid may be withdrawn with a needle and syringe (arthrocentesis). Surgery (arthrotomy) may be required to obtain fluid from some joints (such as the hip) and to treat prosthetic joint infections.

Blood culture.

X-rays, CT (computed tomography) scans, or MRI (magnetic resonance imaging).

How To Treat It

Antibiotics are prescribed to treat bacterial infections and Lyme arthritis. These drugs should be taken for the full term prescribed—which may be as long as six weeks or more in severe cases—even if symptoms subside before that time. Failure to do so can permit the strongest, most virulent strains of the underlying organism to survive and multiply, which may result in an even more severe rebound infection that is harder to treat. For acute bacterial infections, antibiotics are often initially delivered in very high doses by intravenous injection.

Aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) may be administered to reduce pain and inflammation in viral infections.

More potent painkillers, such as narcotics, may be prescribed in severe cases.

Amphotericin B, an antifungal drug, may be used for fungal infections.

For antibiotics to work, the infected joint must be drained—as often as necessary to control swelling (sometimes as often as several times a day).

Surgery (arthrotomy) may be required for fluid drainage of some joints, such as the hip or shoulder.

Infection in a prosthetic joint usually requires removal of the prosthesis. A new joint can be implanted after intensive treatment cures the infection.

Immobilization of the joint is necessary during the healing process. This may require bed rest in addition to a cast or splint.

Physical therapy may be necessary after the infection has subsided, to regain mobility and strength in the affected joint.


From Johns Hopkins Symptoms and Remedies, the complete home medical reference. You can order this book now on our secure server.



Buy now



The arthritis White Paper from The Johns Hopkins White Papers series is an annual, in-depth report written by Hopkins physicians.

Buy now
Johns Hopkins Symptoms and Remedies
An easy-to-use reference work that can help you pinpoint the cause of hundreds of symptoms, from abdominal pain to skin rash to swollen glands.


    Contact us 
    © 2005 Medletter Associates, Inc.