Schnitzler syndrome: a rare cause of systemic urticaria

The Schnitzler's syndrome first described in 1972, associates urticaria, bone pain, and monoclonal IgM gammapathy. A 50-year-old man presented symptoms of urticaria restricted to the trunk and lower members, with episodes of fever accompanied by inflammatory pain in the knees and legs. Slight deterioration of his general condition was also observed. Biological findings showed the existence of an inflammatory syndrome. Electrophoresis and immunoelectrophoresis provided evidence for the existence of underlying IgM gammapathy. Bone X-ray demonstrated the presence of tibial and peroneal metaphysis thickening, with hyperfixation on bone scintigraphy. The patient's condition improved after cortisone and colchicine treatment, allowing decrease in coricosteroid doses. Two years later, except for urticaria, clinical features have disappeared and no hematological disorder has been observed.