Orbital Abscess Complicating Allergic Fungal Rhinosinusitis Due to Streptococcus halichoeri : A Rare Zoonotic Sinonasal Infection

Background: Secondary bacterial infections complicating allergic fungal rhinosinusitis (AFRS) are uncommon but can be serious given the expansile nature of the disease which can thin and erode the bone separating the sinuses from the brain and orbits. Zoonotic pathogens are rarely implicated as pathogens. Case Report: A 21-year-old African American male with several years of progressive nasal obstruction, facial pressure, and hyposmia, presented emergently with acute left eye pain and swelling, diplopia, afferent pupillary defect and inferior visual field deficit. Computed tomography and magnetic resonance imaging demonstrated acute on chronic sinusitis with a left orbital abscess. The patient underwent emergent endoscopic sinus surgery with left orbitotomy and drainage of the orbital abscess. Intraoperative findings, pathology, cultures, and allergy testing were reviewed demonstrating AFRS and a novel zoonotic bacterium, Streptococcus halichoeri . Conclusions: This case represents the first otolaryngologic case of S. halichoeri infection, a severe and complicated sinus and orbital infection. It is unclear if the severity of this infection was a consequence of the unusual pathogen, of the long-term thinning of the bone around the orbit, or both. Although AFRS is not considered an infection, secondary bacterial infection may occur and cause severe complications. Early surgical intervention and culture-directed therapy are essential in managing complicated sinonasal diseases.