A case of urticarial vasculitis associated with macroglobulinemia (Schnitzler's syndrome).

We report a case of urticarial vasculitis associated with macroglobulinemia in a 50-year-old woman. She suffered from intermittent fever with wheals persisting for more than 24 hours. Skin histology revealed perivascular neutrophilic infiltrates with nuclear dusts. Laboratory study demonstrated leucocytosis and a high serum IgM level (2350 mg/dl) with an M component. No overt lymphoid proliferative disease was found. As far as we know, this is the first report of such a case in Japan. Predonizolone and nonsteroidal anti-inflammatory drugs have proved transiently effective for controlling the urticaria, but not for the IgM gammopathy.