Case Report: First reports of Schnitzler syndrome in Iran: clinical presentation and therapeutic challenges

Abstract

Schnitzler syndrome (SchS) is a rare, chronic autoinflammatory disorder characterized by a persistent urticarial rash, intermittent fever, arthralgia, bone pain, and elevated systemic inflammatory biomarkers. Due to its diverse manifestations and overlap with other conditions such as hematologic malignancies, connective tissue diseases, and infections, SchS is often underdiagnosed or misdiagnosed, resulting in delayed appropriate treatment. This report delineates the first two documented cases of SchS in Iran. Both patients exhibited pruritic hives, fever, bone pain, and arthralgia. They were initially diagnosed with chronic idiopathic urticaria (CIU). The diagnosis of SchS was confirmed according to the Strasburg criteria, which included a chronic urticarial rash, monoclonal gammopathy, mild interstitial edema, and an interstitial neutrophilic infiltrate without vasculitis, as observed in the histopathological examination of the dermal lesions. Both patients received subcutaneous omalizumab, a disease-modifying antirheumatic drug (DMARD) such as methotrexate, antihistamines, and corticosteroid drugs. We describe their clinical presentations, diagnostic challenges, and therapeutic strategies, emphasizing the limitations encountered in resource-constrained settings, including restricted access to targeted biologic therapies such as interleukin-1 inhibitors. Our findings underscore the importance of heightened clinical vigilance and comprehensive evaluation of atypical urticarial syndromes to facilitate timely diagnosis and improve patient outcomes.