Escherichia coli sacroiliitis: report of a case and review of the literature.

Pyogenic sacroiliitis is rare and usually occurs in patients with an underlying illness. Typically, the responsible organisms are Staphylococcus aureus or Streptococcus pneumoniae. We describe a healthy 17-year-old boy with bacterial sacroiliitis caused by Escherichia coli. This case illustrates the importance of considering this diagnosis in febrile patients with no obvious source of infection.