IgG4-related sialoadenitis with a skin lesion and multiple mononeuropathies suggesting coexistent cryoglobulinemic vasculitis

A 68-year-old man was admitted because of weakness of the left leg, dysesthesiae of the extremities and bilateral lower extremity purpura. A neurological examination showed mononeuritis multiplex with laboratory evidence of hypocomplementemia, cryoglobulinemia and leukocytoclastic vasculitis in the biopsy of a skin specimen. The patient also exhibited bilateral submandibular gland swelling, elevated serum IgG4 levels and infiltration of a large number of IgG4-positive plasma cells in the submandibular glands. These findings were consistent with both cryoglobulinemic vasculitis and IgG4-related disease. The administration of oral prednisolone (1 mg/kg/day) resolved the neurological manifestations and the swelling of the submandibular glands and cryoglobulinemia.