Discitis

Description

Discitis is an infection in the intervertebral disc space. It affects different age groups.

Signs and symptoms

Symptoms include severe back pain, leading to lack of mobility. In adults, it can lead to severe consequences, such as sepsis or epidural abscess, but it can also spontaneously resolve, especially in children under 8 years of age. Discitis occurs post-surgically in approximately 1–2 percent of patients after spinal surgery. Some very young children may refuse to walk and arching of the back is possible. In post-operative situations, the symptoms occur within a week and result in severe low back pain or neck pain (depending on the surgical location).

If untreated, the discitis may resolve on its own, causing spontaneous fusion of the intervertebral disc space, cause a chronic low grade infection, or progress to osteomyelitis and possibly even an epidural abscess. In case of concomitant inflammation of one or more vertebrae (in such cases usually involving the areas adjacent to the intervertebral disc spaces) the condition is called spondylodiscitis.

Epidemiology

According to a 2008 study, the incidence of discitis in the United States is around 0.4 to 2.4 per 100,000 people each year depending on age group. According to a later 2016 study, the combined prevalence of discitis and vertebral osteomyelitis with or without spinal epidural abscess for persons under 20 years old is uncommon (0.3 per 100,000 persons), and higher in older patients (6.5 per 100,000 persons over 70 years old).

Causes

There is debate as to the cause, although hematogenous seeding of the offending organism is favored as well as direct spread. Spontaneous discitis is usually from hematologic spread from a urinary or respiratory infection while discitis from a post-operative complication usually involves skin flora such as staph aureus. It can be caused due to spinal tuberculosis and spread along spinal ligament to involve the adjacent anterior vertebral bodies, causing angulation of the vertebrae with subsequent kyphosis. The cause may be aseptic.

Diagnosis

Differential diagnosis includes other common causes of back pain and the potential for rarer infections, noting that some differential diagnoses like epidural abscesses and osteomyelitis may be caused by discitis or have a separate cause. This includes:

• Osteomyelitis
• Spinal tumors
• Spinal epidural abscess
• Spinal fracture
• Muscle or tendon injury
• Spinal disc herniation
• Inflammatory spondyloarthropathies

Treatment

Treatment usually includes antibiotics, and reducing the mobility of the affected region, either with a back brace or a plaster cast. Without treatment, the patient may form an abscess which may need to be surgically corrected. Due to the poor vascularity of the disc, drugs required for treatment often include potent agents such as Ciprofloxacin along with Vancomycin. Occasionally, oral drugs can be used to treat the infection but it may fail and IV drugs may be required.

If the patient is an adult, many surgeons and doctors now recommend moving little and often and within the pain limits of the medication. Discs respond to osmotic pressure therefore movement is beneficial to increase their blood flow and fluid dynamics. In children, whether to bed rest or move a little is decided on an individual basis, depending on the site and severity of the discitis.

References

References

1. "Discitis - An Uncommon, Severe Cause of Back Pain".
2. (2015). "CURRENT Diagnosis & Treatment: Physical Medicine & Rehabilitation". McGraw-Hill Education.
3. (2001). "Discitis in young children". The Journal of Bone and Joint Surgery. British Volume.
4. (2007). "Pediatric Orthopedics in Practice". Springer.
5. Muscara, Joseph D.. (2024). "Diskitis". StatPearls Publishing.
6. Chenoweth, Carol E.. (2018). "Vertebral Osteomyelitis, Discitis, and Spinal Epidural Abscess in Adults". Michigan Medicine University of Michigan.
7. (2014). "Davidson's Principles & Practice of Medicine". Elsevier.
8. (2005). "Aseptic discitis in patients with ankylosing spondylitis: A retrospective study of 14 cases". Joint, Bone, Spine: Revue du Rhumatisme.
9. MD, Dave Harrison. (2022-12-31). "Discitis: Definition, Causes, Symptoms, Diagnosis, Treatment, and Prognosis".