Cefazolin-induced hemolytic anemia in septic arthritis: A case report.

A 50-year-old woman living with untreated HIV and injection drug use presented with right shoulder pain. The shoulder exam and computed tomography (CT) scan were concerning for septic arthritis. She was started on empiric vancomycin and cefepime and underwent right shoulder debridement and humeral head resection. Bone cultures grew methicillin sensitive Staphylococcus aureus (MSSA); empiric broad-spectrum antibiotics were changed to cefazolin. The patient subsequently developed severe anemia refractory to blood transfusions approximately 6 days later. Further evaluation disclosed hemolytic anemia attributable to cefazolin. Antibiotic therapy was switched from cefazolin to daptomycin, and the patient was started on prednisone. She had sustained improvement in hemoglobin values above 6 g/dL without requiring further transfusions prior to hospital discharge. Drug-induced immune hemolytic anemia from cefazolin is rare but has been reported primarily in the perioperative setting. Here, we present a case following initiation of treatment for septic arthritis.