and Michael J. Young, M.D.
Discitis, or disc space infection, is an inflammatory lesion of the intervertebral disc
that occurs in adults but more commonly in children. Its cause has been the subject of
debate, although most authors believe it to be infectious. The infection probably begins
in one of the continguous end plates, and the disc is infected secondarily. Severe back
pain that begins insidiously is characteristic of the disease.
Although most children will continue to walk in spite of the pain, young children may
refuse to ambulate. The characteristic finding is extension of the spine and the child's
complete refusal to flex the spine. Children with discitis usually are not systemically
ill. They rarely have an elevated temperature and their white blood cell count is
frequently normal. However the erythrocyte sedimentation rate is usually increased.
Lateral radiographs of the spine usually will reveal disc space narrowing with erosion of
the vertebral end plates of the contiguous vertebrae. bone scanning may be helpful in
localizing a lesion that is difficult to diagnose clinically. Some bone scans are falsely
negative, so the diagnosis of disc space infection should not be excluded simply because
the bone scan is normal. Magnetic resonance imaging (MRI) seems to be helpful in
identifying a disc space infection.
The appropriate treatment of these lesions has been the subject of controversy. Most
authors recommend plaster cast immobilization, a treatment that seems to be effective by
itself in many cases. Some authors think that antibiotics also should be given because the
condition most likely is an infection of the disc (the organism involved is frequently
Staphylococcus aureus). In treating the lesion in children, a biopsy is not usually
necessary. A biopsy may be indicated in adolescents or adults, especially if drug abuse is
suspected, because of the possibility of organisms other than Staphylococcus aureus being
disc infection due to blood-borne bacteria, usually Staphylococcus
aureus, or a low grade viral infection. Older children clinically present with back
pain, similar to adults. The infective focus is in the thoracic or lumbar spine.
Younger children and infants may present with nonspecific abdominal pain, features of
meningism, alteration in posture, or limp. The child may be febrile and ill. Because of
this varied clinical presentation the diagnosis may be delayed. Upper respiratory tract
infection or diarrhoea may precede the illness. The affected disc is in the lumbar spine.
Treatment is bed rest, pain relief and antibiotics, and sometimes immobilization with
plaster jacket. Failure to respond should suggest tuberculosis.
Radiologically, there is disc space narrowing, which may progress to end plate
destruction. Scintigraphy shows generalised increased uptake in the adjacent vertebral
bodies. On MRI, there is increased signal on T2-weighted images and gadolinium enhancement