Infectious arthritis is a form of joint inflammation caused by a germ. The germ can be a bacterium, a virus or a fungus. Infection of the joints usually occurs after a previous infection elsewhere in the body.

There is usually only one joint involved, though sometimes two or three joints can become infected. Mostly, infectious arthritis affects the large joints (shoulders, hips, knees), but smaller joints (fingers, ankles) can also be involved.

Any person, at any age, can get infectious arthritis. However, some people are more likely to get infectious arthritis than others. These include those with conditions that make it difficult to fight off infection, such as:

• diabetes
• sickle-cell anaemia
• severe kidney disease
• AIDS
• immune deficiency
• some forms of cancer
• alcoholism
• intravenous drug abuse

People with an existing arthritis are also more likely to develop infectious arthritis, because germs tend to infect a joint that is damaged, and therefore weaker than a healthy one. If a person has had surgery to replace a joint with an artificial one, this can also provide a slight chance of infection developing. If it does, it usually occurs a short time after the surgical procedure. However, it is not unheard of for infection to show up in a person years after having joint replacement surgery.

Some of the stronger medications used to treat certain types of inflammatory arthritis also lower the body's resistance to infection, making it easier for infectious arthritis to take hold.

People who work in jobs where exposure to animals, plants, marine life and soil is common also have a higher chance of contracting infectious arthritis.

The symptoms of infectious arthritis vary according to the type of germ causing it. If the arthritis is caused by a bacterium, inflammation is generally located in only one place or area. The infection is often accompanied by fever and chills and its onset is quite sudden. With infectious arthritis caused by a virus, there is usually no fever, but there is an aching feeling all over the body. Inflammation caused by a fungal infection can be in one area or throughout the body, and it usually occurs very slowly, over weeks or months. You may have a mild fever or no fever at all.

With infectious arthritis a germ has travelled through the body to a joint. The germ may have entered the body through the skin, nose, throat or ears, or through an existing wound.

Usually, there has already been an infection elsewhere in the body. For example, if you develop infectious arthritis from the bacterium pneumococcus, which causes pneumonia, you may have already experienced pneumonia in the lungs. After the initial infection, the germ can travel through the bloodstream to the joints, where it then settles and causes inflammation.

Bacteria cause most cases of infectious arthritis. The types of bacteria that might cause such infection include:

• gonococcus
• staphylococcus
• streptococcus
• pneumococcus
• hemophilus
• spirochetes
• tuberculosis

Certain viruses can also cause infectious arthritis. They include:

• infectious hepatitis
• mumps
• infectious mononucleosis

Fungi are the least common cause of infectious arthritis. They are usually found in:

• soil
• bird droppings
• certain plants, such as roses

Infectious arthritis is not transmittable from one person to the other, but some germs (such as those causing gonorrhoea and measles) can be spread by person-to-person contact. However, while these diseases can be passed on, this does not automatically mean the development of infectious arthritis is.

Infectious arthritis is usually not a long-term illness. Most of the time it can be cured if it is treated promptly and properly. Without treatment however, the affected joints can become very damaged and the infection can spread to other parts of the body.

Establishing the correct diagnosis is important, so if your doctor thinks you have infectious arthritis, he or she may ask questions about the symptoms, other medical conditions, recent travel, illnesses, and contact with people who may have had infections. He or she may also perform a physical examination, and order x-rays and other tests to find out what germ is causing the infection. This can be done by using a needle to removing a sample of fluid from the joint so it can be examined. If tuberculosis or a fungus is the suspected cause, sometimes a small piece of tissue from the joint may need to be cut away and examined. If a virus is suspected, a blood test may be done because your body develops cells called antibodies to fight off the virus. These antibodies will show up in a blood test.

People with infectious arthritis are often put in the hospital for treatment. Sometimes affected joints must be drained of excess fluid that has built up. This is done by inserting a needle directly into the joint. This procedure is usually painless. Sometimes the same joint may need to be drained several times if fluid build-up recurs. Further treatment varies depending on what type of germ has caused the infection. Your active involvement in developing your treatment plan is essential.

Medicine

NSAIDs reduce pain when taken at a low dose, and relieve inflammation when taken at a higher dose. NSAIDs such as ASA (Aspirin, Anacin, etc.) and ibuprofen (Motrin IB, Advil, etc.) can be purchased without a prescription. Examples of NSAIDs that require a prescription include Naprosyn, Relafen, Indocid, Voltaren, Feldene, and Clinoril. The various NSAIDs and Aspirin®, if taken in full doses, usually have the same levels of anti-inflammatory effect. However, different individuals may experience greater relief from one medication than another. Taking more than one NSAID at a time increases the possibility of side effects, particularly stomach problems such as heartburn, ulcers and bleeding. People taking these medications should consider taking something to protect the stomach, such as misoprostol (Cytotec).

Antibiotics
Antibiotics are usually given for bacterial infections. There are different antibiotics for the different germs. Antibiotics may be taken by mouth or given directly into a vein (intravenously). Sometimes it may be necessary to take the antibiotics over a period of several months. It is important to take all the antibiotics prescribed, even if the symptoms may have been relieved, so that the bacteria do not get stronger and develop a resistance to antibiotics.

Anti-fungal
Infectious arthritis caused by a fungus is the most resistant to treatment. Anti-fungal medications may be prescribed and may have to be taken for months. Surgery to remove the infection from the joint may also be needed. Recurrence of this type of infection is always a possibility.   

Infections
Viral infections cannot be treated with antibiotics. The infections usually resolve themselves on their own. If you have infectious arthritis from a virus you can help the healing process by getting plenty of rest and drinking extra fluids.

Exercise

As the infection subsides, you may be instructed to do exercises that strengthen your muscles. A program of muscle strengthening will help with a favourable recovery. Exercises to improve the range of motion of the joints will also assist with your ability to resume normal activities. Always consult a doctor before beginning an exercise program.

Heat/Cold

Heat or cold application can provide temporary relief of pain. Heat helps to reduce pain and stiffness by relaxing aching muscles and increasing circulation to the area. There is some concern that heat may worsen the symptoms in an already inflamed joint. Cold helps numb the area by constricting the blood vessels and blocking nerve impulses in the joint. Applying ice or cold packs appears to decrease inflammation and therefore is the method of choice when joints are inflamed.

Protect Your Joints

Protecting your joints means using them in ways that avoid excess stress. Benefits include less pain and greater ease in doing tasks. Three main techniques to protect your joints are:

Pacing, by alternating heavy or repeated tasks with easier tasks or breaks, reduces the stress on painful joints and allows weakened muscles to rest.

Positioning joints wisely helps you use them in ways that avoid extra stress. Use larger, stronger joints to carry loads. For example, use a shoulder bag instead of a hand-held one. Also, avoid keeping the same position for a long period of time.

Using helpful devices, such as canes, luggage carts, grocery carts and reaching aids, can help make daily tasks easier. Small appliances such as microwaves, food processors and bread makers can be useful in the kitchen. Using grab bars and shower seats in the bathroom can help you to conserve energy and avoid falls.

Maintaining a healthy weight can also reduce stress on joints, and therefore reduce pain. If you plan to lose weight, discuss the best program for you with your doctor and a dietician.

Relaxation

Developing good relaxation and coping skills can give you a greater feeling of control over your arthritis and a more positive outlook.

Surgery

If your infectious arthritis is caused by a fungus, you and your doctor may consider surgery to remove the infection from the joint.

Along with the physical symptoms of arthritis, many people experience feelings of helplessness and depression. Learning daily living strategies to manage your arthritis gives you a greater feeling of control and a more positive outlook. To get the best results, people affected by arthritis need to form close ties with their doctors and therapists, and become full partners in their treatment. From our perspective, it's all part of 'living well with arthritis.' There are several resources you can use in finding out how best to manage your own arthritis. Here are a few:

• The Arthritis Self-Management Program (ASMP) is a unique self-help program offered by The Arthritis Society to help you better control and manage your arthritis.
• The Open Forum within this Web site is an opportunity to discuss and share information with other visitors - people who, through their own experiences, may be able to offer some useful insights.

Of course, there are many other valuable resources for people with arthritis. If you're unclear about where to look for help, be sure to call The Arthritis Society at 1-800-321-1433.