Schnitzler's syndrome (urticaria and macroglobulinemia) associated with pseudoxanthoma elasticum

Schnitzler's syndrome, first described in 1974, is defined by chronic non-pruritic urticaria, osteocondentation, and a monoclonal IgM dysproteinemia, but without criteria of lymphoproliferative disease. We report a patient with chronic urticaria and macroglobulinemia. In addition, he had double monoconal dysproteinemia IgM kappa (31.3 g/l) and IgA lambda, osteocondensation, and some cutaneous lesions of pseudoxanthoma elasticum. Only 20 cases of Schnitzler's syndrome have been reported hitherto. This is the first case associated with pseudoxanthoma elasticum, which was localized and discovered at the same time as Schnitzler's syndrome. We discuss the possible role of monoclonal immunoglobulin in the occurrence of localized elastorrexhis.