Diagnostic Delay of Schnitzler Syndrome in an Atopic Patient

Schnitzler syndrome (SS) is a rare auto-inflammatory disorder with recurrent episodes of urticarial rash and fever and monoclonal IgM gammopathy as the most common findings. SS has been associated to a high rate of AA amyloidosis and lympho-proliferative disorders but not to any other immune mediated disease. We present a 56 year-old woman with respiratory allergy and pressure urticaria that started to develop episodes of urticarial rashes and fever together with diffuse arthralgias. The blood analysis revealed leukocytosis and monoclonal IgM paraproteinemia. Despite fulfilling criteria for definitive diagnosis of SS, she was not diagnosed and treated with anti-interleukin-1 therapy until two years later. The presence of atopic pre-existing conditions might have contributed to this diagnostic delay. With this report we aim to remark that auto-inflammation and allergy can co-exist in the same patient.