Incomplete Schnitzler Syndrome

Schnitzler syndrome (SS) is a rare autoinflammatory disease that presents with chronic urticaria and monoclonal immunoglobulin (Ig) M or G, accompanied by fever, abnormal bone remodeling, skin biopsy with a neutrophilic dermal infiltrate, leukocytosis, or elevated C-reactive protein. It is usually refractory to antihistamines and immunosuppression. We present a case report of clinical SS without monoclonal Ig with robust response to interleukin-1 inhibitor anakinra. This suggests the possible existence of an incomplete form of SS and underlines the risk of false negative diagnosis in individuals with such "incomplete SS".