Catheter-Related Staphylococcus aureus Bacteremia Complicated by Sternocleidomastoid Muscle Phlegmon and Sternoclavicular Septic Arthritis in a Hemodialysis Patient: A Case Report

Background Staphylococcus aureus bacteremia is a major cause of morbidity in hemodialysis patients, often leading to metastatic complications. Sternocleidomastoid muscle phlegmon and sternoclavicular septic arthritis are uncommon but serious infectious complications of S. aureus bacteremia described in immunocompromised patients but rarely described in patients with end-stage renal disease or an indwelling dialysis catheter. Case Presentation We report a case of a 50-year-old Caucasian woman with end-stage renal disease on maintenance hemodialysis. Her dialysis catheter was removed because of fever and positive blood cultures for methicillin-susceptible S. aureus . Despite a ten-day outpatient course of ceftriaxone and azithromycin, she developed recurrent fever, right-sided neck swelling, trismus, severe lower neck pain, and swelling and tenderness over the sternocleidomastoid muscle. She also had restricted neck movement (torticollis) and a hemorrhagic petechial rash. Odontogenic (dental) or pharyngeal infectious sources were excluded. No internal jugular vein thrombosis was detected at the initial catheter site. Imaging showed a phlegmon in the fascial compartment of the right sternocleidomastoid muscle, septic arthritis of the sternoclavicular joint with erosion of the sternal end of the clavicle, and septic pulmonary emboli with cavitation. The patient underwent surgical incision and drainage of the sternocleidomastoid muscle phlegmon. This was combined with six weeks of targeted intravenous antibiotic therapy and continued hemodialysis. Clinical and radiological improvement was achieved, with complete resolution of the infection and cutaneous manifestations. Conclusion This case shows an unusual pattern of metastatic dissemination in catheter-related S. aureus bacteremia. The complications included a sternocleidomastoid muscle phlegmon and sternoclavicular septic arthritis, both arising by contiguous spread from the infected catheter tunnel, together with septic pulmonary embolism and a hemorrhagic rash. The case underscores the need for early recognition, prompt source control, and aggressive, multidisciplinary management, including early surgical intervention, for high-risk hemodialysis patients.