[Sweet syndrome. Acute neutrophilic dermatosis in multiple myeloma].

A 64-year-old woman complained of reddish plaques that had suddenly appeared on her upper arms and trunk. Histological investigation revealed perivascular distribution of a neutrophilic infiltrate in the upper and mid-dermis; direct immunofluorescence showed deposits of C3 and fibrin in and around the vessels. Laboratory values in the blood, X-ray of the head and fine-needle biopsy of the hip showed the typical pattern of multiple myeloma.