Septic arthritis in the name given to describe a joint that has been invaded by bacteria, fungi, or virus that has migrated to the site from another infected part of the body via the bloodstream. Most commonly, this occurs after suffering an infection of the urinary or respiratory tract. However, septic arthritis can also be caused by the infection of a wound, injection, or surgical site, or a direct injury that penetrates the joint.
This condition is also known as infectious arthritis, pyogenic arthritis, viral arthritis, and suppurative arthritis, with slight variances in etiological meaning between them depending on the foreign substance responsible. However, they all share a common factor that distinguishes septic arthritis from degenerative arthritis, which is the accumulation of pus in the lining of the joint.
There are a number of bacteria that can cause septic arthritis, including that which produces gonorrhea. However, the most common culprit is Staphylococcus aureus. Since this bacterial strain is found in abundance on human skin and in mucous membranes, it explains how it can be easily introduced into the bloodstream. Other strains found to be associated with septic arthritis include Escherichia coli, Salmonella spp., Streptococci, and Mycobacterium tuberculosis.
Typically, only one joint becomes infected with septic arthritis, usually a knee, hip, or shoulder joint. This is referred to as monoarthritis. However, it is possible for several joints to become infected at the same time, especially in cases where Neisseria gonorrhoea or Streptococci are involved. It’s also possible to experience an immune response to the presence of infection that affects joint function without the joint becoming directly infected at all. This type of infectious arthritis is known as reactive arthritis.
Several risk factors may make one more prone to developing septic arthritis than others. For instance, those with autoimmune disorders or who must take immunosuppressive medications are at greater risk for infection overall. The presence of non-infectious arthritis or gout may also increase risk. Other disorders are associated with a higher incidence of septic arthritis, such as lupus, diabetes, and liver and kidney disease. In addition, chronic skin conditions, such as eczema and psoriasis, may also increase risk.
The symptoms of septic arthritis are similar to other forms of arthritis, most notably pain and inflammation of the joint. However, it is much more likely that additional symptoms will occur that are not associated with other forms of arthritis. These include fever, chills, and the site itself feeling hot to the touch. It’s important to pay attention to the latter in particular, especially if red streaks appear on the surface of the skin. In fact, this may be the only clue that septic arthritis is present since taking medications to reduce pain and inflammation of the joint may cause one to escape notice of a fever.
Septic arthritis treatment typically involves the use of antibiotics designed to check the specific bacteria, fungi, or virus that led to infection. In addition, the physician may also extract joint fluid with a needle in a procedure called arthrocentesis. There are two primary reasons for performing this procedure. First, it reduces inflammation at the joint. Secondly, it affords the physician the opportunity to monitor the site while undergoing therapy until no further traces of the infection is found.