Schnitzler's syndrome: monoclonal gammopathy associated with chronic urticaria.

ABSTRACT

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.