Septic arthritis is infectious arthritis, the cause of infection being microbes such as bacteria, virus and fungi. The microorganisms make the joint fluid of one or more joints infected. Bacteria such as Staphylococcus aureus and Haemophilus influenzae are the most common causes of septic arthritis. Other bacteria that cause the disorder include mycobacterium tuberculosis and the spirochete bacteria. In extreme cases, E. coli and Pseudomonas spp. also cause septic arthritis. The viral reasons for septic arthritis are Hepatitis A, B and C, herpes viruses, HIV, parvovirus B19, HTLV-1 and adenovirus. Septic arthritis is caused by fungi varieties such as coccidiomyces, histoplasma and blastomyces.
Certain ‘risk situations’ are identified which are found to be favourable for the development of septic arthritis. Medications taken to suppress the immune system, previous joint disorders, sickle cell diseases, intravenous drug abuse etc are some of these risk situations. In people who have these risk conditions, ‘unusual joints’ may be affected. In normal case, the joints prone to septic arthritis are larger ones such as knees, ankles, hips, and elbows.
Apart from joint pain, the other major symptoms of septic arthritis are chills, swelling, stiffness, redness and fever. It is by the verification of the joint fluid that septic arthritis is diagnosed. After collecting a sample of this fluid, it is analysed in a laboratory. An increased number of white blood cells in the fluid indicate inflammation. Apart from WBC count, sedimentation rate and C-reactive protein are also considered during the blood test. An advanced culture of the fluid will bring to light the kind of the infection caused.
Doctors prescribe antibiotics as part of the treatment of septic arthritis. The medication depends upon the lab result of the joint culture. The infected joint fluid gets drained away completely. The drainage is usually affected with a needle and syringe. In case of any complication, open joint surgery is done to clear the infected joint.