[Monthly low-dose immunoglobulin infusion as a maintenance therapy for multifocal motor neuropathy may reduce allergic adverse effects: a case report].

A 41-year-old man with multiple motor neuropathy developed weakness of the left hand at the age of 35 years. The weakness gradually progressed to his right hand. High-dose intravenous immunoglobulin (IVIg) therapy (0.4 g/kg for 5 consecutive days) improved the muscle weakness in the hands but led to the development of generalized severe pompholyx that spread to the skin over the entire body. Because muscle weakness of the hands worsened several months after IVIg therapy, we attempted another course of IVIg therapy. However, antiallergic agents and oral corticosteroids did not suppress the pompholyx induced by the high-dose IVIg. Hence, the treatment was switched to low-dose immunoglobulin therapy (0.4 g/kg for one day) once every month. After more than 8 months of low-dose therapy, only mild form of pompholyx remained and the muscle strength was maintained without further deterioration.