A Case of Methicillin-Sensitive Staphylococcus aureus (MSSA) Prostate Abscess, Osteomyelitis, and Myositis Associated with MSSA Bacteremia in a 60-Year-Old Patient Presenting with Back Pain.

BACKGROUND Staphylococcus aureus (SA) is a rare cause of prostatic abscess. Risk factors include genito-urinary instrumentalization and immunocompromised states. Because of the lack of guidelines on the diagnosis, management, and follow-up of SA prostate abscess, the diagnosis can sometimes be challenging. Our patient was a 60-year-old man who initially presented with lower back pain and was diagnosed with a methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia, prostate abscess, osteomyelitis, and myositis. CASE REPORT A 60-year-old man presented with lower back pain. He had a past medical history of incompletely treated MSSA cervical osteomyelitis with epidural abscess, alcohol use disorder, intravenous drug use (IVDU), and poorly controlled diabetes mellitus (DM). He was afebrile and hemodynamically stable. Laboratory test results revealed leukocytosis and an elevated C reactive protein (CRP). Lumbar spine magnetic resonance imaging (MRI) showed vertebral osteomyelitis and right psoas myositis. Blood cultures isolated MSSA. The patient was treated with vancomycin and piperacillin-tazobactam. On day 5, our patient reported having fever, chills, flank pain, and dysuria. Computed tomography (CT) revealed a 4.0×4.9 cm prostatic abscess. CT-guided percutaneous abscess drainage was performed, and fluid culture revealed MSSA. Both antibiotics were discontinued and cefazolin was started following sensitivities. Post-drainage pelvic ultrasound (US) showed resolution of the abscess. CONCLUSIONS This case highlights the importance of a rapid diagnosis of SA prostate abscess in patients with documented risk factors and characteristic symptoms. Timely management with antibiotics and drainage as indicated are imperative to avoid further complications from the underlying bacteremia, including sepsis and metastatic infections.