Idiopathic orbital myositis in a pediatric patient and treatment

Abstract

Idiopathic orbital myositis is an autoimmune orbital disease characterized by one or more non-granulomatous, non-infectious, non-neoplastic extra-ocular muscle inflammation whose etiology was unknown. A 9-year-old male patient was admitted to our clinic with diplopia and a pain in left-gaze starting 3 days ago. There was a restriction in left-gaze in the left eye and diplopia in the examination of eye movements. The other gaze direction were normal in both eyes movements. Minimal edema was also detected in the left eyelid. Orbital MRI was asked for the preliminary diagnosis of idiopathic orbital myositis, thyroid eye disease, and orbital cellulitis. It was a marked thickening detected in the orbital MRI left medial rectus muscle. Owing to thyroid function tests are in the normal range thyroid ophthalmopathy were excluded and in orbital MRI; Orbital cellulitis were excluded because of the fact that there were no orbital abscess and sinusitis findings and also no extra-ocular infiltration outside the left medial rectus muscle. 30 mg/day of oral prednisolone therapy was started after diagnosing with idiopathic orbital myositis. At the end of the first week, the restriction in left-gaze and the diplopia was completely improved. Ocular movement limitation starting with acute pain and diplopia are rarely seen in pediatric patients and can easily be overcome as a subgroup of the observed idiopathic orbital myositis and the non-specific orbital inflammation (NSOI). Thanks to a careful examination and MRI imaging system, orbital myositis should be one of the diagnoses being considered. Thus, late diagnoses, use of redundant antibiotics, and unnecessary biopsies can be avoided.