Thalidomide may be an effective drug for Blau syndrome: a case report.

Blau syndrome (BS) is a monogenic autoinflammatory disease caused by mutations in nucleotidebinding oligomerization domain containing 2 (NOD2). BS is characterized by the clinical triad of granulomatous dermatitis, arthritis and recurrent uveitis. Due to the low incidence of BS and the lack of treatment studies with large samples, a specific treatment scheme has not been established. We report the case of a patient with BS that was uncontrollable with various immunosuppressive therapies but had a good response to thalidomide. She had the typical triad of rash, arthritis and uveitis. Gene sequencing indicated a NOD2 heterozygous missense variant (c.1759C > T, p.R587C), which has been reported as a pathogenic mutation. The BS diagnosis was confirmed. After treatment with methotrexate, an anti-tumour necrosis factor (TNF)-α inhibitor and corticosteroids, the patient's clinical symptoms and inflammatory indicators remained uncontrolled, and she experienced multiple side effects, such as hypertension and growth retardation attributed to prolonged corticosteroid use. After treatment with thalidomide, her condition was controlled without recurrence or side effects, and corticosteroids were stopped as soon as possible. This report suggests that thalidomide may be effective for BS treatment, but more research is needed to evaluate its long-term efficacy and side effects.