A Rare but Fascinating Disorder: Case Collection of Patients with Schnitzler Syndrome.

BACKGROUND: Schnitzler syndrome is a rare disorder characterized by a chronic urticarial rash and monoclonal gammopathy (IgM in more than 90% of the cases). It is difficult to distinguish from other neutrophilic urticarial dermatoses, and diagnosis is based on the Strasbourg criteria. Interleukin-1 is considered the key mediator, and interleukin-1 inhibitors are considered first line treatment. Here, we present two cases of Schnitzler syndrome, both successfully treated with anakinra.

OBJECTIVES: To increase awareness regarding clinical presentation, diagnosis, and treatment of this rare disorder.

CASES: We describe the clinical features and disease course of two patients with Schnitzler syndrome, diagnosed using the Strasbourg criteria. Both were treated with anakinra with remarkable response to therapy.

CONCLUSION: Schnitzler syndrome is a rare and underdiagnosed disorder. High suspicion should be maintained in patients with chronic urticaria-like dermatoses, intermittent fevers, and arthralgias. A serum protein electrophoresis and immunofixation should be performed in these patients. The diagnosis is important to recognize as Schnitzler syndrome is associated with malignancy. A lymphoproliferative disorder develops in about 20% of patients at an average of 7.6 years after onset of symptoms. Thus, patients warrant long-term follow-up. IL-1 inhibitors are extremely effective in relieving symptoms and are considered first line therapy.