Pneumococcal sacroiliitis.

We report an unusual case of Streptococcus pneumoniae sacroiliitis in a previously healthy 31-year-old woman. Six cases of pneumococcal sacroiliitis have been reported; the only two cases in adults occurred in young women in the preantibiotic era. Our patient had fever and a depressed level of consciousness, with subsequent right buttock and thigh pain. Blood cultures revealed S pneumoniae, and a bone scan showed increased tracer activity in the right sacroiliac joint. Although the cerebrospinal fluid white blood cell count was only 3/microL, culture of cerebrospinal fluid grew S pneumoniae. Our patient was successfully treated with a 6-week course of intravenous antibiotics (penicillin G after an initial week of ceftriaxone), followed by 2 weeks of oral penicillin therapy.