[A patient of recurrent orbital myositis with good response to high-dose intravenous immunoglobulin (i.v.-i.g.) therapy].

We report a 62-year old woman with orbital myositis who had a favorable response to intravenous immunoglobulin (i.v.-IG) administration in preventing disease recurrence. She had been suffering from frequent relapses of swelling and redness of the left eye with increasing pain and diplopia caused by restricted eye movement of the left eyeball. T2-weighted magnetic resonance image of the orbit showed enlargement of the left medial rectus muscle. She was treated with 1 g of methylprednisolone per day for 3 days. One mg/kg per day of oral prednisolone was subsequently started with non-steroid anti-inflammatory drugs, which resulted in improvement. However, her symptoms were aggravated while the drug was tapered off even though she used a high dose of oral prednisolone. High dose of i.v.-IG (400 mg/kg per day) was then administered for five days. Since the treatment, she has been free from recurrences of the disease for over one year, suggesting that i.v.-IG can prevent the recurrence of orbital myositis. Some reports have suggested that i.v.-IG treatment is useful to prevent recurrence of other forms of inflammatory myositis, such as dermatomyositis or polymositis. Overproduction of the pro-inflammatory cytokines (IL-1, IL-1 beta, INF-alpha) and Th1 cytokines (INF-gamma, IL-2) are related to the deterioration of these diseases. I.v.-IG treatment suppresses the production of the pro-inflammatory cytokines. In our case, serum levels of the pro-inflammatory cytokines were all normal, but the IL-4 level was elevated after the i.v.-IG treatment, suggesting that orbital myositis was probably related to the Th1 dominant disease that was suppressed by IL-4.