Schnitzler's syndrome: Monoclonal gammopathy associated with chronic urticaria

Schnitzler's syndrome (SS) is defined by monoclonal gammopathy and chronic urticaria combined with at least two of the following features: fever, arthralgia or arthritis, bone pain, hepato-and/or splenomegaly, palpable lymph nodes, elevated ESR, and leukocytosis. We report a 49-year-old man with monoclonal IgM gammopathy and a 4-year history of recurrent urticarial rash, unexplained fever and arthralgias. The skin biopsy from an acute lesion revealed perivascular lymphocytic infiltrates consisting of CD4+ and CD8+ T lymphocytes. To our knowledge, this is the first report of an immunophenotypic characterization of skin infiltrates in SS. A lower CD4+/CD8+ ratio of circulating T lymphocytes was also detected. SS usually has a benign course, but in 15% of patients a lymphoproliferative disorder develops. Copyright (C) 2008 S. Karger AG, Basel.