Exaggerated lordosis and refusal to walk; don't forget the spine!

Dear Sir,

Discitis is an infection or inflammation of the vertebral end-plate or intervertebral disc. It's a rare condition usually involving children <5 years of age and almost exclusively only involves the lumbar spine. In this case report we aim to present an unusual presentation of discitis in a toddler and have discussed its etiology and management.

A 23 month old previously well child presented with 2 weeks history of refusal to walk. There was no preceding history of trauma or fever. During the 1st week of illness, she was seen by health professionals on three separate occasions and underwent investigations in the form of blood infection markers and ultrasound of her hips all of which were normal except for raised erythrocyte sedimentation rate (35). Provisional diagnosis of irritable hip was made, and the parents were informed to return if still not better in a weeks time. On her presentation mum mentioned that the child appears in constant pain and has recently started refusing to lie on her back, preferring to lie on her side or on her tummy.

On her assessment, she was apyrexial, alert and with normal neurological examination including lower limb tone, reflexes and down-going plantars on both sides. There was a full range of movements along her hip joints with no discomfort. With one hand held, she could walk for a short distance demonstrating significantly exaggerated lumbar lordosis. There was associated tenderness along the lower lumbar spine and spasms of para-spinal muscles.

X-ray spine [Figure 1] and magnetic resonance imaging (MRI) spine [Figure 2] with contrast clinched the diagnosis of discitis involving lumbar disc 2–3 region. She made a complete recovery with 2 weeks of intravenous, followed by 4 weeks of oral antibiotics.

Figure 1

Lateral X-ray spine demonstrating narrowing of the L2–L3 disc space (arrow)

Figure 2

Magnetic resonance imaging whole spine T2 sagittal view-note the destruction of L2–L3 intervertebral disc clearly visible (arrow)

Discitis is an infection or inflammation of the vertebral end-plate or intervertebral disc. It's a rare condition usually involving children <5 years of age and almost exclusively only involves the lumbar spine.[1] It's often difficult to diagnose, especially in toddlers as they may be un-cooperative and are unable to give a history. The precise etiology is uncertain, but is thought to be mostly infective in origin.[2] Noninfective process and trauma mechanisms have also been suggested.[3] Staphylococcal aureus is the most common organism isolated from both blood as well as biopsy cultures from the disc tissue.[1] The yield from the open or needle biopsy is usually poor, with a positive culture rate ranging from 0% to 67%.[24]

Clinical features are usually nonspecific and include refusal to walk (63%), inability to flex lower back (50%), back pain (27%), and either loss or exaggerated lumbar lordosis.[15] The most common initial misdiagnosis reported is irritable hip as seen in our case. It should be differentiated from vertebral osteomyelitis [Box 1]. MRI is an investigation of choice with positive findings, including loss of disc height, abnormal disc signal or destruction of the disc.[1]

Box 1

Differentiating between discitis and vertebral osteomyelitis

Management involves joint care with orthopedic team and treatment with broad-spectrum intravenous antibiotic (e.g. ceftriaxone) for 2 weeks, followed by 4 weeks course of oral antibiotic (amoxicillin and flucloxacillin) is generally recommended.[1] If there is no clinical improvement, biopsy should be considered and antibiotic should be changed following microbiologist advice.

In countries where tuberculosis is endemic, like Indian subcontinent, in cases like the one reported, when an MRI shows an infected process of the disc space, it may be wiser to get a sample for microbiology and pathology before instituting antibiotics.

Prognosis is excellent with complete clinical recovery if diagnosed and managed early. Delay in diagnosis may lead to neurological complications secondary to spinal nerves and/or cord compression.

We recommend that the discitis should be considered in any child presenting with refusal to walk and abnormal posturing and early use of MRI spine to establish the diagnosis.