Unilateral septic sacroiliitis caused by

Brucellosis is one of the most common zoonotic diseases, presenting with a wide range of clinical manifestations. The most common symptoms include undulating fever and musculoskeletal issues. Frequent complications tend to involve osteoarticular surfaces, leading to spondylitis, osteomyelitis, and peripheral arthritis. Septic arthritis is another serious complication, the early diagnosis of which can be challenging, especially in the postpartum period, as the symptoms are often non-specific and easily misinterpreted. A 21-year-old female presented to our clinic in the fourth week of her postpartum period with severe unilateral buttock pain. She was sub febrile and had no apparent abnormalities on a pelvic X-ray. The pain was intense to the point that she could not walk properly. Sacroiliac MRI during the acute pain episode revealed mild bilateral sacroiliac (SI) joint effusion, predominantly on the right side, with bone marrow edema in the sacral and iliac aspects of the right SI joint, accompanied by some articular erosions and adjacent myofascial edema. The patient tested seropositive for brucellosis and completely recovered with antibiotic therapy. The patient was under follow-up for 3 months and she underwent a significant remission in symptoms with her pain substantially reduced. Brucella sacroiliitis should be considered in postpartum patients presenting with unilateral buttock pain that is unresponsive to analgesics and associated with difficulty walking.