Polyarticular septic arthritis caused by Staphylococcus lugdunensis in a patient with systemic lupus erythematosus.

Septic arthritis in patients with systemic lupus erythematosus (SLE) is rare and is reported in only 3% of patients. Contrary to lupus arthritis, which tends to be polyarticular in nature, primarily involving the small joints of the hands, septic arthritis is commonly monoarticular. Here, we present an unusual case of a patient with SLE, who developed oligoarticular inflammatory arthritis caused by a rare native joint pathogen Staphylococcus lugdunensis. The infection resulted in extensive early damage to the joints involved, highlighting the need for early diagnosis and treatment.