Disseminated Nocardia otitidiscaviarum presenting as septic arthritis in a nephrotic syndrome patient on immunosuppressants

Abstract

Rationale: Septic arthritis due to Nocardia is rare, with Nocardia otitidiscaviarum being the rarest Nocardia species isolated from septic arthritis. Patient concerns: Here we present a case of a 47-year-old man with a history of nephrotic syndrome on active treatment who developed signs and symptoms of septic arthritis. Diagnosis: Initial Laboratory test results showed high inflammatory markers, Right knee joint ultrasound revealed effusion. Therefore, knee arthrocentesis was performed, which revealed a milky orange fluid that grew gram-positive branching forms identified as moderate Nocardia otitidiscaviarum. Despite being asymptomatic, the patient underwent Head computed tomography, which revealed dissemination to the brain. Intervention: The patient was started on appropriate antibiotics, immunosuppressant medications were stopped, and arthroscopic drainage was performed. Outcomes: Repeated arthrocentesis after 2 weeks was sterile. After 1 month, the patient felt better, pain-free, and was able to ambulate. Lessons: Nocardial arthritis is rare, and joint management requires an internist, a rheumatologist, a surgeon, and an infectious disease expert because early identification of the bacteria can improve the outcomes and quality of life.