Missing red flags in back pain—tuberculosis of the spine: an important differential for back pain in non-endemic countries
- 1Emergency Department, Imperial College Healthcare Trust, London, UK
- 2Emergency Department, Plymouth NHS Trust, Plymouth, Devon, UK
- Correspondence to Dr Matt Alwyn Edwards,
Chronic back pain is an extremely common complaint. All primary care physicians will be on the lookout for the ‘red flags’ that suggest serious pathology. The diagnosis of spinal infection with tuberculosis (TB) is uncommon and often not considered, especially in areas where the rate is very low such as the south west of England. We describe a patient presenting to the emergency department with severe pain, immobility and with a sensory deficit level. Unfortunately, given the favourable results for early medical treatment for spinal TB, this patient presented late and had a very poor outcome.
Frequently patients with spinal tuberculosis (TB) present several times to doctors before referral for investigation of spinal TB is made.1 In the county of Devon this will more often be the case as it has one of the lowest rates of TB in the UK.2 Delayed diagnosis is the characteristic of the disease3 as is misdiagnosis, and can result in complications including severe kyphosis and debilitating neurological compromise.4
A 44-year-old female care home worker of Philippine origin, with a 3-month history of worsening thoracolumbar back pain, presented to the emergency department with fever and urinary disturbance. During the past months she had been virtually immobile owing to constant severe pain, prescribed maximal analgesia including neuropathic medication, and had become very concerned when she could not pass urine and noticed she could no longer sense temperature below the level of her umbilicus. On examination she had fever 38.4°C and was immobile because of pain. She had no spinal tenderness except minimal paraspinal spasm. The only consistent abnormal neurological finding was a sensory loss of temperature discrimination below the spinal level of the thoracic spinal nerve 10 (T10). She had a postmicturition urinary volume of 450 ml. There was good preservation of her motor function. TB was suspected when it was revealed that she had worked as a nurse in the Philippines prior to working in the UK.
Chest x-ray showed no lung field shadows but there was subtle angulation and loss of height at T6. An urgent MRI (Ofigures 2 and 3) demonstrated a large destructive lesion encompassing the vertebral bodies of T6 and T7 and compressing the spinal cord. A CT guided biopsy of the lesion revealed an acid-fast bacillus by day 2. She was screened as HIV negative.
With a conclusive diagnosis of spinal TB, 1 year programme of ethambutol, pyridoxine and rifampicin was started.
Outcome and follow-up
The initial plan was for bed rest and medical management but unfortunately the spinal cord signs progressed and despite surgical decompression and fusion the patient developed paraplegia.
The vast majority of episodes of back pain are self-limiting and require no intervention.6 Infrequently back pain represents serious pathology including infection, malignancy or systemic inflammatory disease.8 ,9 One such rare aetiology is spinal TB, which is often not considered in non-endemic areas,1 and especially not in areas like Devon, where this patient was presented.2
The incidence of TB is increasing worldwide10 including developed countries.11 Skeletal disease constitutes the second most common extrapulmonary manifestation of the disease, and half of these cases involve the spine4 otherwise known as ‘Pott's disease’ (named after the surgeon Percival Pott in 177612). It is important to note that thoracic pain is a common presentation of spinal TB as it most commonly affects the thoracic spine, followed by the lumbar spine.4
In the UK, TB is commonly encountered in ethnic groups originating from areas of high endemicity,1 ,13 in particular South Asia (55%) and sub-Saharan Africa (30%).11 It is thought that the increased risk of developing TB for immigrants becomes that of the host population after 5 years14; however, evidence suggests that up to one-third of these new cases have been resident for more than 10 years.1
TB in general is curable. The current mainstay of the treatment is chemotherapy (ie, isoniazid, rifampicin and pyrazinamide for at least 6 months). Indications for surgery (debridement, laminectomy and fusion) include failure of medical treatment, paraspinal abscesses, spinal instability, neurological deficit, as demonstrated in this case, and kyphosis of >30°.15
Consider the ‘red flags’ for every patient with chronic back pain.
The incidence of tuberculosis (TB) is rising in the UK even in the areas such as Devon.
Spinal TB is characteristically diagnosed late but that does not mean it has to be.
Early detection of spinal TB could prevent permanent disability and deformity.
The author would like to acknowledge Mr Nicholas Haden, Consultant Neurosurgeon, Derriford Hospital, Plymouth NHS Trust.
Contributors All the three authors involved with the care of the patient with MAE being the original responsible clinician. MAE wrote up the case and learning points. MH provided much of the literature review. DA advised, reviewed and edited the manuscript.
Competing interests None.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.