Idiopathic Lateral Rectus Myositis Without Signs of Orbital Inflammation.

Idiopathic orbital inflammation (IOI), also known as orbital pseudotumor, is a nonspecific term that represents inflammation of unknown etiology that could affect various orbital structures. We report a case of IOI with an atypical presentation mimicking other clinical conditions. Our patient did not show the typical signs of inflammation that are usually seen in patients with orbital pseudotumor and are paramount in its diagnosis. Hence the diagnosis of IOI should be considered in the differential diagnosis of periorbital pain even when clinical signs of orbital inflammation are absent.