[Septic sacroiliitis: early diagnosis due to specific physical examination].

Background: Septic sacroiliitis is an uncommon disease which represents approximately 1-4% of all joint infections, therefore it is difficult to make the right diagnosis and to start early treatment.

Case Report: A 18 year old woman was admitted to the emergency room with a fever and pain in the left gluteal region. The patient was considered healthy and had no risk factors for septic arthritis.