Efficacy of interleukin-1 blockade in Schnitzler's syndrome without detectable monoclonal gammopathy: a case-based review.

Schnitzler's syndrome (SchS) is a rare autoinflammatory disorder characterized by urticarial rash and monoclonal gammopathy which is currently regarded as IL-1 mediated disease. We present the case of a 21-year-old woman presenting with urticarial rash, arthralgias, and elevated inflammatory markers. She has been suffering these symptoms for 2 years and was treated with antihistamines, omalizumab, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) without success. After an extensive diagnostic workout, we suspected SchS even without monoclonal gammopathy, and started Anakinra 100 mg daily with a dramatic response and achieving complete remission after 48 h of the beginning of the treatment, so we decided to confirm SchS diagnosis. We performed a search of the literature and found seven more cases of patients diagnosed with SchS without monoclonal gammopathy at the presentation. Five were treated with IL-1 blocking therapies and all achieved remission. We, therefore, prompt the possible role of IL-1 blockade therapy remission as support in diagnosing SchS without monoclonal gammopathy.