Bilateral infraorbital nerve involvement in idiopathic orbital myositis.

We describe a case of bilateral infraorbital nerve involvement in idiopathic orbital myositis. Computed tomographic scanning of the orbits showed enlargement of extraocular muscles consistent with orbital myositis and enlargement of the ipsilateral infraorbital nerve. With disease progression, infiltration of the contralateral infraorbital nerve also developed. Biopsies of the inferior oblique muscle and infraorbital nerve showed the same inflammatory infiltrate: a mixed population of lymphocytes (B and T) with B cells expressing kappa and lambda light chains. Although orbital myositis may be associated with several conditions, to the best of our knowledge, this is the first time a case of idiopathic orbital myositis with bilateral infraorbital nerve involvement has been described.