Spontaneous subperiosteal orbital hematoma in a patient with chronic sinusitis

Periorbital swelling is a common presentation to the emergency department (ED), and its etiology can range from benign to acutely vision-threatening. Orbital subperiosteal hematoma is a rare ED diagnosis that is typically associated with trauma, though can infrequently occur spontaneously in the setting of sudden elevations in cranial venous pressure, bleeding diathesis, and sinusitis. We present a case of a 55-year-old female with a history of chronic sinusitis who presented to the ED with a three-day history of left-sided periorbital swelling along with painful extraocular movements and markedly decreased visual acuity following a cross-country road trip through elevation. Contrast computed tomography scan of the orbits revealed a large extraconal collection in the subperiosteal space causing significant mass effect on the left globe, along with findings of diffuse sinonasal disease bilaterally. Intravenous antibiotics were started immediately and the patient underwent surgical incision and drainage of the subperiosteal space, where she was diagnosed with a spontaneous subperiosteal orbital hematoma secondary to chronic sinusitis. Within the literature, there are fewer than 20 case reports of orbital subperiosteal hematoma secondary to sinusitis. The purpose of this case report is to assist emergency physicians in considering the rare but potentially vision-threatening condition of spontaneous subperiosteal orbital hematoma within their differential diagnosis of patients with periorbital swelling and proptosis, as well as to provide an approach to management within the ED.