A Case of Orbital Abscess Caused by Prevotella baroniae Infection

Purpose: We report a case in which <i>Prevotella baroniae</i>, an oral pathogen, was transmitted to the orbit, leading to the development of orbital abscess.Case summary: A 56-year-old female presented with persistent ocular pain, eye movement limitation, periorbital swelling and erythema on the left eyelid. The patient had a history of aplastic anemia and had undergone sequestrectomy surgery for maxillary osteomyelitis and exposed sinus bone on the left side of the face in the past. Orbit magnetic resonance imaging revealed irregular enhancement and disruption of the left orbital floor, indicative of cellulitis. The patient was thus diagnosed with periorbital cellulitis and orbital abscess. Debridement was performed, and purulent discharge was observed and a culture was performed. The culture identified <i>P. baroniae</i>, suggesting a spread of infection from oral, dontogenic infection to the orbit. The patient showed improvement after intensive antibiotic treatment.Conclusions: Orbital abscesses should be treated with appropriate necrotic tissue debridement, drainage, and intensive and effective antibiotics. This is the first report of an orbital abscess caused by orbital transmission of <i>P. baronii</i>, an oral infection, in Korea.