Infectious arthritis, also known as septic arthritis, is a form of arthritis that occurs when microorganisms attack one or multiple joints. Usually infectious arthritis affects a single joint of the body. Occasionally, several joints are attacked by microbes. Children and elderly people are most susceptible to infectious arthritis.
Infectious arthritis is curable if treatment begins within the first week after the arthritis develops. Bacterial infections of the joints are the most common cause of infectious arthritis. Viral and fungal infections account for a smaller number of infectious arthritis cases. Knees are the most common site of infectious arthritis caused by bacteria. Other joints of the body including the ankles, elbow, hip and wrist are also vulnerable to microbe invasion.
Causes of Infectious Arthritis
Rarely bacteria directly attack a joint of the body. In most cases, infectious arthritis due to bacterial infection occurs when an infection that begins in another part of the body such as the urinary tract or respiratory tract spreads to the blood. The bacteria in the bloodstream is transported to the joint, where it lodges, grows and multiplies, leading to inflammation and pain of the affected joint. Several strains of bacteria are associated with infectious arthritis.
Gonococcus is a type of bacterium that causes the sexually transmitted disease gonorrhea. When present in the bloodstream, it can travel to other parts of the body, including the joints. The synovium or the lining of the joint are not strong enough to shield the underlying joint tissues from the bacteria, which easily invades the synovium to settle in the cartilages and the joint fluid.
They also attack the bursae and the tendons. It may take a few days up to several weeks for the symptoms of infectious arthritis to appear after the first symptoms of gonorrhea develop. Compared with male gonorrhea patients, women are more susceptible to gonococcus infections of the joints. Delay in treatment causes severe damage to the joints.
Staphylococcus bacteria are frequently linked to infectious arthritis. The bacteria primarily attack the upper respiratory tract. Occasionally, it spreads to the joints. Staph infection is more likely to occur following sinus or skin infection. It may even occur after surgery.
This form of infectious arthritis is more likely to occur when the immune system is weakened by an underlying illness. People with rheumatoid arthritis or any other autoimmune disease on immunosuppressant drugs have a higher risk of developing staph infections.
Lyme disease is a type of infectious arthritis caused by a strain of the bacterium spirochetes. It is caused by tick bites. It is more common in children.
Other Bacterial Infections
Infectious arthritis can also occur when bacteria associated with pneumonia, meningitis and tuberculosis attack the joints. The bacterium hemophilus linked to meningitis and throat infections are associated with infectious arthritis in babies.
Infectious arthritis caused by viruses heals naturally without treatment within a few weeks. Viruses associated with German measles, infectious mononucleosis, hepatitis and mumps are common causes of viral arthritis.
Infectious arthritis is rarely linked to fungal attack. Exposure to bird dropping and certain plants may cause fungal arthritis.