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Diskitis is an uncommon inflammatory condition affecting the intervertebral disc and adjacent vertebral end plates. The available evidence implicates a low-grade bacterial infection rather than a noninfectious inflammatory process, as was previously thought. Most cases are diagnosed in children younger than 4 years, in the age range between 7 months and 16 years,1–8 and males are more frequently affected (male to female ratio is 1.7:1).6–8 Diskitis involves the lumbar spine most commonly, although any area of the spine may be involved. As the findings on history and physical examination are often nonspecific, a high index of suspicion is required to make the diagnosis.
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While several theories have been proposed including infection, noninfectious inflammation,9,10 and trauma,11 the weight of evidence implicates a bacterial infection involving the disc and vertebral end plate.1,6,9,12–14 This theory is supported by cultures of intervertebral material and blood.1,6,8–10,14 Diskitis likely represents one end of the spectrum of infection involving the anterior elements of the spine, the manifestations of which depend upon differences between the microcirculation in infants and children versus adults. Vascular channels between the vertebral body and the disc are present in infants and children, providing a portal for hematogeneous seeding of the disc. These channels are not present in adolescence and adulthood, which explains the preponderance of vertebral osteomyelitis rather than diskitis in these older age groups. While diskitis may resolve spontaneously in a subset of patients treated only by symptomatic measures, the disease process may progress and require operative debridement.12,15,16 Ring et al. found recurrent symptoms and/or a prolonged course in 18% of patients with diskitis treated with intravenous antibiotics versus 67% who received no antibiotics.12
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The clinical findings associated with diskitis differ infants and toddlers, compared with older children (Table 49–1). The presentation in infants/toddlers is usually nonspecific, often resulting in a delay in diagnosis. Occasionally, parents may report a recent infectious illness (e.g., upper respiratory tract infection) or a mild trauma. Symptoms in the infant and toddler include general irritability, crying at night, and the refusal to walk. When severe, symptoms may result in the refusal to stand or sit with a preference for bed rest.1,3,6,13 Older children with diskitis often experience well-localized back pain, which may radiate to the hip region or legs. Gait disturbance is a common finding in this age group,5,7,9 and pain may be referred to the abdominal region.
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