Group B Streptococcus Bacteremia Mimicking Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis (SAPHO) Syndrome.

Group B Streptococcus (GBS) causes septic arthritis in healthy adults, and a significant number of GBS septic arthritis cases involve multiple joints. Nevertheless, septic arthritis is commonly monoarticular. Here, we report a case of a 45-year-old man who complained of subacute fever and right shoulder and right buttock pain for three weeks despite undergoing garenoxacin treatment for one week. Although synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome could be a possible differential diagnosis for this patient, the fever and subacute clinical course could not be explained. Blood cultures revealed the presence of GBS; therefore, he was diagnosed with septic arthritis. After antibiotic treatment for six weeks, his symptoms resolved.