Blau Syndrome (Juvenile Systemic Granulomatosis): State-Of-The-Art Review

Blau syndrome (BlauS) is a rare pediatric autoinflammatory disorder due to NOD2 gain-of-function pathogenic variants characterized by a triad of granulomatous dermatitis, arthritis, and uveitis, which can progress to systemic complications if untreated. Skin and joint findings typically emerge by age 2 years, with ocular involvement appearing around age 4 years. Early biologic intervention, particularly with anti-TNF-α therapies, can prevent severe complications like joint destruction and blindness. Systemic corticosteroids serve as bridging therapy, while methotrexate and thalidomide may help but are often insufficient as monotherapy. IL-1 and IL-6 inhibitors, as well as tofacitinib, are options for refractory cases.