A 33-year-old woman presented to a community emergency department with a 4-day history of monocular orbital pain, photophobia and pain on extraocular movement. Findings included chemosis, conjunctival injection and restricted extraocular movements causing strabismus. She was diagnosed with orbital cellulitis during her initial emergency department visit and treated with intravenous antibiotics. On her second ED visit later the same day, a diagnosis of orbital pseudotumour was made after computed tomography revealed inflammation of the sclera, optic nerve, muscle and adipose tissue within the orbit. Antibiotics were discontinued and tapering steroids were initiated, with prompt resolution of symptoms.

Orbital abscess of rhinosinogenic origin may develop, either by contiguous spread of the infection or by a thrombophiebitic process. While destruction of the bony walls of the paranasal sinus occurs in propagation of the infection by tissue continuity, haematogenous spread may take place through intact bone. Computed tomography demonstrates the status of the bony partitions shared by the orbit and paranasal sinuses, and the source of the orbital sepsis, thereby influencing the therapeutic approach.