Nonspecific Orbital Inflammation

Excerpt

Orbital pseudotumor, also known as orbital inflammatory pseudotumors (OIP), idiopathic orbital inflammation (IOI), orbital inflammatory syndrome (OIS), idiopathic orbital inflammatory pseudotumor (IOIP), or nonspecific orbital inflammation (NSOI) is a benign, space-occupying, and non-infectious inflammatory condition of the orbit but may extend in the peri-orbital area. There is no identifiable infectious, systemic, or neoplastic disorder. It is the third most common orbital disease in adults, after thyroid orbitopathy and lymphoproliferative diseases. A significant number of orbital inflammations may be associated with systemic conditions or remote organ dysfunction. Categories of orbital pseudotumor according to location include anterior, diffuse, posterior, or apical. Other classifications include myositis, dacryoadenitis, periscleritis, perineuritis, and focal mass.

Orbital pseudotumor is rare in children. The most common ophthalmic findings are periorbital edema and blepharoptosis. A palpable mass may be present. On orbital radiography, common findings are dacryoadenitis, orbital mass, or myositis. In children, systemic signs are present in up to 50% of patients. Headache, emesis, anorexia, lethargy, and fever are the most common systemic signs. Additionally, there are likely associations with iritis, uveitis, disc edema, and peripheral eosinophilia.