[Spondylodiscitis as a dominant early symptom of juvenile ankylosing spondylitis]

A 12-year-old female (HLA-B27 negative) presented with unilateral low back pain and sterno-clavicular arthritis. Six months after onset the clinical and radiological findings determined spondylodiscitis L1/2. On the basis of the clinical findings (oligoarthritis, symptomatic sacroilitis, spondylodiscitis), juvenile ankylosing spondylitis was suspected. The diagnosis was corroborated 18 months after the first occurrence of symptoms by the appearance of typical changes in the sacroiliac joint that are indicative of juvenile ankylosing spondylitis. Because of persisting antibodies against Borrelia burgdorferi, the possibility of B. burgdorferi-induced reactive arthritis with involvement of the axial division of the skeletal system was considered. After 3.5 years of observation the condition showed a benign course with radiologically observable consolidation of the spondylodiscitis. To our knowledge, this is the second case described of juvenile ankylosing spondylitis with spondylodiscitis as a dominating feature.