Caveats and truths in genetic, clinical, autoimmune and autoinflammatory issues in Blau syndrome and early onset sarcoidosis.

Blau syndrome (BS) and early onset sarcoidosis (EOS) are, respectively, the familial and sporadic forms of the pediatric granulomatous autoinflammatory disease, which belong to the group of monogenic autoinflammatory syndromes. Both of these conditions are caused by mutations in the NOD2 gene, which encodes the cytosolic NOD2 protein, one of the pivotal molecules in the regulation of innate immunity, primarily expressed in the antigen-presenting cells. Clinical onset of BS and EOS is usually in the first years of life with noncaseating epithelioid granulomas mainly affecting joints, skin, and uveal tract, variably associated with heterogeneous systemic features.

Blau syndrome, clinical and genetic aspects.

Blau syndrome (BS) is a rare autosomal dominant, autoinflammatory syndrome characterized by the clinical triad of granulomatous recurrent uveitis, dermatitis and symmetric arthritis. The gene responsible for BS has been identified in the caspase recruitment domain gene CARD15/NOD2. In the majority of patients, the disease is characterized by early onset, usually before 3-4years of age.

Extranodal Rosai-Dorfman disease: involvement of eye, nose and trachea.

Rosai-Dorfman disease (RDD) is a rare non-neoplastic histiocytic proliferative disorder characterized by painless lymphadenopathy. Extranodal lesions frequently occur in the head and neck regions. We report the clinical and histological features of extranodal RDD in a 43-year-old man with a previously unreported combination of multiple gross anterior epibulbar nodules in the right eye, submucosal masses of nasal septum and trachea, and no lymphadenopathy during the 12-year follow-up.