[Schnitzler's syndrome]

Schnitzler syndrome (SS) is a rare clinical entity, which belongs to the spectrum of monoclonal gammapathy-associated systemic disorders. Its pathophysiology remains elusive, even if it is tempting to consider it as a late onset and probably acquired auto-inflammatory syndrome. SS mainly occurs in the fifth and sixth decade, and present with an urticariform rash with periodic fever and/or osteoarticular pain. Systemic inflammation and monoclonal gammapathy (overwhelmingly IgM kappa) are constant features. SS is a chronic disease, which can severely impair quality of life of the affected individuals. Many drugs have been used and proved disappointing. In the last few years, accumulating reports provided evidence for the dramatic efficacy of anakinra, which has revolutionized the management of most severe cases. The main long-term threat to these patients is to develop a lymphoproliferative disorder (mainly Waldenström's macroglobulinemia). The mechanisms underlying the different facets of the disease remain to be elucidated.