Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Schnitzler syndrome ?
    ### Response:
    Schnitzler syndrome is a rare autoinflammatory condition. Signs and symptoms of the condition vary but may include urticaria; recurrent fevers; joint pain and inflammation; organomegaly (abnormally enlarged organs); and/or blood abnormalities. The exact underlying cause of the condition is unknown; however, most cases occur sporadically in people with no family history of the condition.
    