Discitis or spondylodiscitis is an uncommon disease which causes pain and discomfort in the spinal region due to infection of the vertebrae or intervertebral disc space. The intervertebral discs act as a cushioning material, separating the vertebrae from each other. Therefore, infection and inflammation in this space can be distressing. Inadequate blood supply in the spinal disc area remains a major problem, reducing the capability of the immune system to fight off the infection. Treatment therefore becomes difficult in this area, however delay in treatment can lead to serious complications.
Causes and risk factors of Discitis
Discitis is often a bacterial infection but sometimes it can be a viral or fungal infection. There are mainly two possible mechanisms through which these spinal discs get infected. They are:
Direct infection: This can occur as a result of an intervention at the spinal disc site. These may include procedures carried out for diagnostic, surgical and therapeutic purposes.
Spread of infection from other sites (Spontaneous Discitis): Bacterial/viral Infection can spread through the blood to the vertebrae and spinal discs from other infected sites. These may include urinary tract infections, respiratory infections, pelvic infections or other systemic infections.
Other risk factors include:
- Spread from adjacent localised infection
- Weak immune systems (Uncontrolled Diabetes, Cancer, AIDS etc.)
- Autoimmune diseases
- Intravenous drugs
Signs and Symptoms of Discitis
The typical signs and symptoms of Discitis include:
- Fever
- Severe, unbearable back pain
- Stiffness in the back region
- Localised pain at the infected disc area
- Abdominal pain
- Pain does not spread to the legs as in other spine disorders
- Pain increases with movement
Diagnosis of Discitis
Discitis is diagnosed based on medical history, physical examination, laboratory tests and diagnostic imaging scans.
Physical examination: Physical examination includes assessment of areas of tenderness at the infected site, evaluation of range of motion and pain-triggering movements.
Laboratory tests: Blood samples are taken to identify typical signs of infection and inflammation such as raised white blood cells (WBC) counts, increased erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Blood cultures are used to detect the presence of microorganisms (bacteria, virus, fungi etc) in the blood.
Diagnostic imaging: Although X-rays do not show any signs until few weeks of onset of the disease, they are used to assess the disc space and vertebral segments. The most accurate tool for diagnosing discitis is an MRI which will clearly reveal and existing infection.
Treatment of Discitis
The initial treatment of discitis involves intravenous (IV) administration of broad spectrum antibiotics. Once the blood culture results are obtained, antibiotics specific to the causative organism are given. The antibiotic-course lasts for about 4-6 weeks. Pain relief medication such as Non-Steroid Anti-Inflammatory Drugs (NSAIDs) are given for reduction of pain.
Bed rest and back braces are recommended for proper alignment, fusion and stabilization of the vertebrae.
Surgery is rarely indicated, but when required it involves thorough cleaning and removal of infected tissues and foreign material to promote healing and growth of healthy tissue.
