Association of oral flora with orbital complications of acute sinusitis.

Background: Acute and chronic sinusitis in children and adults can spread to the orbit. Oral flora has been seen in orbital infections, but the extent of synergy between pathogens in such infections remains unknown.

Methods: A retrospective case series of patients with complicated sinusitis that involved the orbit from acute sinusitis who were admitted to a tertiary care hospital from January 2000 to December 2014 and who had surgical cultures obtained. Patients were identified by the International Classification of Diseases, Ninth Revision code for periorbital cellulitis, subperiosteal abscess, or orbital abscess.

Results: Sixteen patients underwent surgical drainage via external drainage or endoscopic sinus surgery of an orbital infection associated with sinusitis and had cultures obtained. Nine patients (56%) grew organisms that exist in oral flora, whereas seven patients (44%) grew common respiratory pathogens. The most common organisms recovered were viridans group streptococcus (VGS) (50%), Staphylococcus aureus (31%), Eikenella corrodens (25%), and Prevotella species (19%). Oral flora anaerobes were cultured alongside a VGS species in seven of eight patients (88%) as opposed to the respiratory pathogens, which were less frequently associated with concomitant VGS infection (29%) (p = 0.04).

Conclusion: There are two main sources for infectious orbital complications from acute sinusitis: respiratory pathogens and oral flora. The high prevalence of concurrent anaerobic oral flora and VGS infection supports a suspected synergy between VGS and other oral organisms.