A case of recurrent Mikulicz's disease with mononeuritis multiplex

We report an 82-year-old man with recurrence of Mikulicz's disease accompanied with mononeuritis multiplex. On admission, both upper eyelids, the salivary gland, the dorsum of the left hand and both legs were swollen. Neurological examination showed motor weakness of distal limbs (manual muscle testing 3/5) and decreased touch, pain and vibration sensation of the dorsum of the left hand and both legs. Deep tendon reflex in both legs was also decreased. We diagnosed Mikulicz's disease based on high serum immunoglobulin (Ig)G4 (630 mg/dl, 26.1% of total IgG) and lacrimal gland biopsy findings. Clinical symptoms and motor conduction study findings improved after steroid therapy. However, tapering of the steroid dose resulted in recurrence two years later. Steroid therapy is usually effective for IgG4-related neuropathy, and we found that an increase of steroid dose was effective to treat the recurrence. But, in general, a suitable maintenance dose of steroid in combination with an immunosuppressant may be necessary to prevent relapse.