Septic arthritis is an infection of the joint that leads to arthritis. It is commonly caused by bacteria such as Group B Streptococcus or Staphylococcus aureus, which is the bacterium responsible for MRSA.
The staph A often colonizes in the nasal passages and in people with strong immune systems does no harm, but it can sometimes enter the blood stream and attack joints, or even lead to blood poisoning.
What Causes Septic Arthritis?
Septic arthritis can be caused by:
• Infection of the nose or throat, traveling to the blood and joints
• Trauma – bacteria can get into the blood via injury
• Surgery – it can be a side-effect of surgical procedures to the joints
It is most common in people with poor immune systems, such as those with pre-existing illnesses or those having chemotherapy, elderly people, people who inject illicit drugs, those with a history of joint surgery such as a hip replacement operation, and those with an untreated sexually transmitted infection.
Untreated gonorrhoea can enter the bloodstream and cause septic arthritis.
• Joint pain
• Redness and swelling of the affected areas
• Fever and feeling ill
• In some cases, low blood pressure, feeling faint.
• If untreated, the person can sustain permanent joint damage and disability or even develop septicaemia (blood poisoning) which can kill, so prompt treatment is important.
There are several ways to test for septic arthritis.
Joint Aspiration: Some fluid from the joint is drawn off with a needle and analysed for pathogens.
Tissue Culture: A biopsy of tissue could be taken to check for fungal infections.
Blood Tests: Blood samples would be taken to check for blood infections.
STI Tests: If you think you may have a sexually transmitted infection, you will also be given blood tests and swabs for these.
X-rays and MRI’s: These can check the condition of the joints.
Antibiotic treatment should begin immediately even before the doctor has got the results of any tests. This is because septic arthritis can result in permanent disability and may lead to blood poisoning.