A Comprehensive Review of Schnitzler Syndrome

Schnitzler syndrome is a rare disorder characterized by a chronic red, hive-like rash and elevated levels of a specific protein in the blood (monoclonal IgM gammopathy). Symptoms associated with Schnitzler syndrome may include recurrent bouts of fever, inflammation of the joints (arthritis), joint pain (arthralgia), bone pain, and other findings such as enlarged lymph nodes (lymphadenopathy). Most cases of Schnitzler syndrome have a chronic, benign course. However, over a 10-year period, approximately 15% of people with the condition develop cancer, often caused by an overproduction of white blood cells (lymphoproliferative disorders) such as Waldenström macroglobulinemia. The exact cause of Schnitzler syndrome is unknown. Researchers believe that certain parts of the immune system may not function properly, ultimately causing Schnitzler syndrome. People with Schnitzler syndrome also have a clinical finding called monoclonal IgM gammopathy, in which abnormalities affecting the production of immunoglobulins lead to increased levels of immunoglobulin M (IgM) in the body. The first-line treatment for mild cases is nonsteroidal anti-inflammatory drugs (NSAIDs). But this is often not enough. In more severe cases, standard treatment is with therapy to inhibit the cytokine IL-1.