Infectious arthritis, also known as septic arthritis, is a form of joint pain that manifests from an infection in a joint. This is caused by an infection that began elsewhere in the body, affecting the particular joint in question, leading to arthritic symptoms.
Systemic infections such as Lyme disease, hepatitis, fifth disease, mumps, German measles, and rheumatic fever can trigger the development of infectious arthritis. Infants and older adults are most likely to be affected by this condition, with the knee being the most commonly affected joint.
There are generally two types of infectious arthritis: acute and chronic.
Acute: Caused by bacteria that begins quickly. It accounts for 95 percent of infectious arthritis. It can affect healthy people as well as people at high risk for getting an infection. Cartilage found within joints and required for normal function can become damaged within hours or days.
Sometimes, infections of this caliber can occur away from the joints, in areas such as the genital organs or digestive organs, and are reactions to another infection and is called reactive arthritis.
Chronic: Begins gradually over several weeks and accounts for five percent of infectious arthritis and most often affects people who are at high risk. Most commonly infected joints include the knee, shoulder, wrist, hip, elbow, and the joints in the fingers. Most bacterial, fungal and mycobacterial infections affect only one joint or, occasionally, several joints.
The presentation of this condition may vary from case to case, but the following are the most commonly seen signs and symptoms:
Septic arthritis is most commonly caused by bacteria that travels through the blood stream to an area in the body. They are either staphylococcal or streptococcal.
These bacteria may enter a wound or infect the joint directly after injury or surgery. The following things that increase the chances of developing septic arthritis are:
Having one or a combination of these risk factors increases the chances of developing septic arthritis complications.
Existing joint problems: Chronic diseases and conditions that affect the joints, including osteoarthritis, gout, rheumatoid arthritis, or lupus. Having an artificial joint, previous joint surgery, or a joint injury can also increase risk.
Rheumatoid arthritis medications: These medications tend to suppress the immune system, creating an opportunity for infectious bacteria to invade the body and making the development of septic arthritis more likely. Also, diagnosing septic arthritis in individuals with rheumatoid arthritis is difficult because many of the symptoms and signs are very similar.
Skin fragility: Skin that breaks easily and heals poorly can give bacteria easy access. Skin conditions such as eczema and psoriasis increase the risk of septic arthritis. IV drug abusers also have a higher risk.
Weak immune system: Having an immune system that is compromised opens the possibility of becoming infected. This includes individuals with diabetes, kidney and liver problems, and those taking immunosuppressive medications.
Joint trauma: Animal bites, puncture wounds, or cuts over a joint can increase the risk of developing septic arthritis.
Once at the doctor’s office, they will examine the joint for any visual abnormalities and ask you questions about the symptoms you may be experiencing.
This will only go so far in diagnosing the condition, as lab testing will be needed to find out what kind of bacteria is currently causing the infection and what medication will be the most effective. This is done by arthrocentesis—a test frequently used to diagnose this condition and involves inserting a needle into the affected area to take a sample of the synovial fluid. This fluid is then taken to a lab for testing.
The doctor may also take a blood sample, checking the white blood cell count—a marker for infection.
Imaging testing may also be done to assess the possible joint damage done by the infection and may include an x-ray, MRI, CT scan, or nuclear scan.
The use of antibiotics for infectious arthritis treatment is generally the most common course of action. The identification of the most likely infectious organism will dictate which is the best medication to use to fight off the particular bacteria.
Infections need to be treated promptly and aggressively to prevent osteoarthritis and damage to the joint. This may require the use of IV antibiotics, which are much more effective than their oral variants.
Many people with infectious arthritis will need to have their synovial joint fluid drained. This is done to remove the infected fluid, ease the pain and swelling, and prevent further damage to the joint. Synovial fluid is often drained using arthroscopy and is done by making several small incisions near the affected joint and using a tube to suction out the fluid.
Sometimes doctors use a small needle to remove infected fluid without requiring surgery.
Occasionally, surgery is required to remove any damaged sections of the joint or replace the joint altogether.
Other treatment methods to reduce pain may be used along with treatment for infection, including:
Choosing to not see a doctor when experiencing the symptoms of septic arthritis can be one of the worst decisions a person can make. Losing the function of one of the larger joints on the body is simply just the start, as the infection can spread and lead to fatal consequences. When in doubt, get a doctor’s opinion to decrease septic arthritis recovery time and improve septic arthritis prognosis.
Lyme disease: The best way is to avoid the ticks that transmit the disease. This can be achieved by wearing long sleeve shirts and long pants. You can also use tick repellent. Avoiding the woods, brush, and other areas with ticks is perhaps the best advice to completely avoid the condition.
Gonococcal arthritis: Practice safe sex or abstinence
Staphylococcal arthritis: The use of antibiotics once a staph infection has been recognized will help you avoid this type of arthritis.
Viral arthritis: Perform all the actions you do when trying to avoid a viral infection. This includes washing your hands frequently. Not indulging in injection drugs will help you stay away from infections such as Hepatitis B and C, as well as HIV.