A 63–year–old man with type 2 Diabetes and recent diagnosis of high grade Myelodysplastic Syndrome, presented with one week of progressive left eyelid swelling and erythema. He had an associated clear discharge and left–sided temporal headache. He denied fevers, eye pain, vision loss or any recent upper respiratory or sinus infections. Physical exam was remarkable for severe eyelid swelling and erythema with associated chemosis, proptosis and restricted extraocular movements. His visual acuity was normal. Laboratory studies were significant for pancytopenia. CT scan of the orbits revealed a post–septal cellulitis with adjacent ethmoid sinusitis and extraocular muscle myositis. There was no fluid collection or evidence of cavernous sinus thrombosis. He was started on vancomycin and pipercillin/tazobactam in addition to posaconazole for empiric coverage of invasive fungal infection given his immunocompromised status. On hospital day (HD) #2, the patient acutely developed complete loss of vision in his left eye. He was taken to surgery emergently for debridement. Intraoperative cultures were obtained and antifungal coverage was broadened with Amphotericin B. Cultures grew Rhizopus. On HD #5, he regained partial vision.
Orbital cellulitis is an infection of the soft tissues of the orbit posterior to the orbital septum. It is most often associated with spread from an infected ethmoid sinus. Other etiologies include direct inoculation by trauma or surgery and hematogenous spread from bacteremia. The most common pathogens are Staphylococcus and Streptococcus species, Hemophilus influenzae, and less commonly, anaerobes, Aspergillus and Mucor. The challenges are that invasive fungal infections can present similarly to bacterial orbital cellulitis. Mucormycosis must be suspected in those patients with diabetes, hematologic malignancies, and chronic immunosuppression. Opthalmology and ENT consultation is paramount. Prompt surgical debridement is warranted with development of an orbital abscess, vision loss, culture isolation of a fungus, or failure of medical management within the first 24–36 hours. The hallmarks of successful treatment are early diagnosis, antifungal therapy, aggressive surgical debridement, and treating the underlying disease.
This case underscores the importance of timely diagnosing orbital cellulitis, recognizing the patient population at greatest risk for invasive fungal infection, and the need to act urgently in the setting of clinical deterioration. There are no randomized controlled trials evaluating empiric treatment regimens for those with orbital cellulitis and most common treatment regimens focus on the most common pathogens. In any immunosuppressed patient with orbital cellulitis, the physician should harbor a high index of suspicion for Mucormycosis, and initiation of early anti–fungal therapy, in addition to antibiotics, should be heavily considered.