[Septic sacroiliitis: case report].

Bacterial pyogenic sacroiliitis is a relatively rare infection that may be difficult to diagnose. A delay in the diagnosis may be associated with marked toxemia and demanded surgical drainage of the septic joint. We report clinical and laboratorial findings in a 12-year-old white girl with onset low back and leg pain two weeks before admission to the hospital. Bone scintigraphy showed increased uptake in the right sacroiliac joint and radiologic changes were typical of sacroiliitis. Oxacilin-sensitive S. aureus was cultured from fluid of surgical biopsy. Antibiotic treatment leads to complete recovery after long time with low back pain. The diagnosis and treatment of this rare disease are discussed based upon our finding and the literature data.