A Rare Case of Concomitant Septic Arthritis, Osteomyelitis, and Pyomyositis Caused by Salmonella

A common causative organism in osteomyelitis in sickle cell disease is Salmonella. Septic arthritis and muscle infection due to Salmonella are much less common. We present a case of a 28-year-old woman with sickle cell disease who presented with left shoulder and elbow pain for two days. Physical examination revealed swelling of the left upper arm. The patient was initially treated for a sickle cell pain crisis. On hospital day 4, the patient developed a fever. She empirically started intravenous vancomycin and cefepime before her blood culture showed Salmonella. Subsequently, the antibiotic was changed to ceftriaxone. Synovial fluid analysis of the left shoulder revealed a white blood cell count of 53,250/mm³ with mostly neutrophils, and this led to a presumptive diagnosis of septic arthritis. She underwent a left shoulder arthroscopic irrigation and debridement. The synovial fluid culture was negative. Magnetic resonance imaging (MRI) revealed osteomyelitis in the left humerus, a 4.4 x 5 cm intramuscular abscess near the distal anterior humerus, and pyomyositis. Percutaneous abscess drainage was done. The patient was discharged home on ceftriaxone but returned 12 days later with worsening pain in her shoulder. Repeat MRI showed a complex glenohumeral joint effusion. She had an incision and drainage of her left shoulder. The patient was discharged on an eight-week course of ceftriaxone. Prompt diagnosis and early treatment are essential in reducing the mortality and morbidity associated with these joint, bone, and muscle infections.