First case report of <i>Corynebacterium minutissimum</i> septic arthritis associated with an indwelling device

<i>Corynebacterium minutissimum</i> usually presents with erythrasma, a macular rash, but rarely it can cause extracutaneous infections such as endocarditis, peritonitis, pyelonephritis, and catheter-related bloodstream infections. Here, we present the first case of septic arthritis caused by <i>C. minutissimum</i> and a literature review of invasive <i>C. minutissimum</i> infections. The diagnosis was confirmed by the patient's clinical findings and microbiological examination of the joint fluid. Considering the patients hemodialysis catheter and the pathogenic nature of the <i>C. minutissimum</i>, we strongly suspected a catheter-related infection. Clinical and laboratory follow-ups showed consistent improvement with treatment, characterized by reduced pain, swelling, and localized warmth in the left knee, along with a significant decline in acute-phase reactants. The patient achieved full recovery following a four-week course of antibiotics and catheter removal. Our report emphasizes the importance of not disregarding the isolation of non-diphtheria <i>Corynebacterium</i> from appropriately collected sterile samples in symptomatic patients, particularly those with indwelling devices. Based on this case report, clinicians should consider the rare possibility of this microorganism being the cause of septic arthritis.