Actinomyces Orbital Osteomyelitis in the Setting of Multiple Myeloma and Bisphosphonate-Related Osteonecrosis

Actinomyces is a genus of filamentous, branching gram-positive bacteria that are commensal organisms in the oral cavity, although they may become invasive in both immunocompetent and immunocompromised patients (1). Infection may extend from cervicofacial foci along tissue planes, through the foramina or directly through bone, yet Actinomyces is a rare cause of orbital infection (2-4). We describe a patient with orbital osteomyelitis and vision loss in the setting of bisphosphonate-related osteonecrosis of the jaw (BRONJ), a poorly understood disease process that has been linked to Actinomyces osteomyelitis.