RESUMEN
BACKGROUND: Polyarticular septic arthritis (PASA) accounts for approximately 15% of all septic arthritides and is rare in immunocompetent adults. Even with appropriate therapy PASA's mortality rate is nearly 50%. CASE REPORT: We report a rare presentation of PASA caused by idiopathic septic thrombophlebitis of the brachiocephalic vein in an immunocompetent adult female patient who presented with symptoms of right clavicular, left wrist, and right hip pain associated with fevers. Methicillin-sensitive Staphylococcus aureus was isolated in blood cultures and joint aspiration of one of the affected hips. Transesophageal echocardiogram was negative for valvular vegetations and computed tomography chest with contrast revealed thrombi in the brachiocephalic and subclavian veins extending to the superior vena cava. It also showed bilateral pulmonary nodules consistent with septic pulmonary emboli. No clear precipitant for the underlying septic thrombophlebitis was identified. Management was conservative, with systemic anticoagulation and IV antibiotics. The patient's symptoms improved, and she was discharged to subacute rehabilitation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Early diagnosis and treatment of PASA in the emergency department is imperative to reducing overall morbidity and mortality associated with this condition. To the best of our knowledge, this is the only case report of idiopathic septic thrombophlebitis of the subclavian vein causing PASA in an immunocompetent adult.