Chronic Tophaceous Gout Masking Methicillin-Sensitive Staphylococcus aureus Bacteremia

A 91-year-old woman with chronic tophaceous gout presented with worsening left foot pain, swelling, and purulent drainage after several months of presumed gout flares treated with prednisone and antibiotics. At presentation, she was septic with leukocytosis, elevated inflammatory markers, and imaging consistent with first metatarsophalangeal (MTP) osteomyelitis. Blood cultures grew methicillin-sensitive Staphylococcus aureus (MSSA). Further imaging demonstrated T12/L1 discitis and lumbar epidural phlegmon/abscess extending from L3/L4 to L5. Echocardiography showed a small filamentous structure on the mitral valve where vegetation could not be excluded. This case showcases diagnostic uncertainty when infection mimics gout and the need for early reassessment when symptoms fail to respond to conventional treatments.