Schnitzler's syndrome associated with pancreatitis: a disease of IL-1 dysregulation.

Schnitzler's syndrome (SS) is a rare inflammatory disease of unknown origin characterized by chronic urticaria and monoclonal gammopathy (usually IgM) associated with at least two of the following components: fever, arthralgia or arthritis, bone pain, hepato- and/or splenomegaly, lymphadenopathy, elevated erythrocyte sedimentation rate, leukocytosis, and/or abnormal findings on bone morphological investigations. To date, about 100 cases have been described with only 4 being reported in the USA. The mean time to diagnosis from the onset of disease is 5.4 years, given the varied symptoms with which patients may present. The pathogenesis of SS remains unknown but likely involves dysregulation of the IL-1 pathway. We describe here a 48-year-old woman with a monoclonal IgM gammopathy and a 3-year history of chronic pruritic urticarial dermatosis, unexplained fevers, chronic polyarthritis, lymphadenopathy, leukocytosis, hepatomegaly, and weight loss. She also had a history of chronic pancreatitis as well as a family history of recurrent pancreatitis. The diagnosis of Schnitzler's syndrome was made, and she was successfully treated with the IL-1 receptor antagonist, anakinra.