Managing Yao Syndrome: A Case of Beneficial Treatment with Upadacitinib and Leflunomide

Yao syndrome, an autoinflammatory disease associated with specific NOD2 gene variants, presents with a wide range of symptoms, including fever, dermatitic rashes, polyarthritis, abdominal pain/bloating, and sicca symptoms. The initial clinical manifestation remains widely variable. The first-line treatment options remain unknown due to limited knowledge of the pathophysiology and the absence of robust literature. We report a case of a 36-year-old woman diagnosed with Yao syndrome, presenting with postprandial bloating, followed by polyarthralgia and low-grade fever. After experiencing reactions to treatments, including anaphylaxis secondary to anakinra and canakinumab, the patient showed improvement with upadacitinib and leflunomide, resulting in better control of her symptoms.