[Schnitzler syndrome is a diagnostic challenge].

Schnitzler syndrome (SS) is a rare autoinflammatory disorder characterized by a chronic urticarial rash and a monoclonal immunoglobulin M gammopathy, accompanied by recurrent fever, lymphadenopathy, arthralgia or arthritis, hepato- or splenomegaly and elevated levels of markers of systemic inflammation. Because patients often present to various specialists with different symptoms the syndrome is often undiagnosed, and it can take years before the correct diagnosis is made. Treatment with interleukin-1 receptor antagonists has a rapid effect on SS.