With that information the diagnosis of BS was not only determined by phenotype but now by genotype.Early onset sarcoidosis is BS without a family history,  BS has been diagnosed in patients who have not only the classic triad but granuloma in multiple organs. See also
List of cutaneous conditions

References
Further reading
Wouters CH, Maes A, Foley KP, Bertin J, and Rose CD: Blau Syndrome, the prototypic auto-inflammatory granulomatous disease. Pediatric Rheumatology 2014;12:33. PMID 25136265. PMC 4136643.  doi:10.1186/1546-0096-12-33. Blau EB : Familial Granulomatous Arthritis, Iritis, and Rash. The Journal of Pediatrics 1985; 107: 689-693. PMID 4056967.  doi:10.1016/s0022-3476(85)80394-2. Jabs DA, Houk JL, Bias WB, and Arnett FC: Familial Granulomatous Synovitis, Uveitis, and Cranial Neuropathies. The American Journal of Medicine 1985; 78: 801–804. PMID 3993660.  doi:10.1016/0002-9343(85)90286-4. Malleson P, Schaller JG, Dega F, Cassidy SB, and Pagon RA : Familial Arthritis and Camplodactyly. Arthritis and Rheumatism 1981; 24: 1199–1204. PMID 7306244.  doi:10.1002/art.1780240915. Rotenstein D, Gibbas DL, Majmudar B, and Chastain EA: Familial Granulomatous Arteritis with Polyarthritis of Juvenile Onset. The New England Journal of Medicine 1982; 306: 85–90. PMID 7053492.  doi:10.1056/NEJM198201143060208. Pastores GM, Michels VV, Stickler GB, Su WP, Nelson AM, and Bovenmyer DA: Autosomal dominant granulomatous arthritis, uveitis, skin rash, and synovial cysts. The Journal of Pediatrics 1990; 117: 403–408. PMID 2391595.  doi:10.1016/s0022-3476(05)81080-7. Tromp G, Kuivaniemi H, Raphael S, et al. : Genetic Linkage of Familial Granulomatous Inflammatory Arthritis, Skin Rash, and Uveitis to Chromosome 16. The American Journal of Human Genetics 1996; 59: 1097-1107. PMID 8900239. PMC 1914842.
Blau syndrome is an autosomal dominant genetic inflammatory disorder which affects the skin, eyes, and joints. It is caused by a mutation in the NOD2 (CARD15) gene. Symptoms usually begin before the age of four, and the disease manifests as early onset cutaneous sarcoidosis, granulomatous arthritis, and uveitis. Presentation
Cause
The elucidation that the gene defect in Blau syndrome (BS) involves the CARD15/NOD2 gene has stimulated many investigators to define how this gene operates as part of the innate immune system. The innate immune system recognizes pathogen-associated molecular patterns (PMAPs), including bacterial polysaccharides such as muramyl dipeptide, via its pattern recognition receptors (PRRs), such as NOD2, to induce signaling pathways that activate cytokine responses and protect the organism. In BS the genetic defect seems to lead to over activation and poor control of the inflammatory response leading to widespread granulomatous inflammation and tissue damage. Diagnosis
Treatment
Treatment has included the usual anti-inflammatory drugs such as adrenal glucocorticoids, anti-metabolites and also biological agents such as anti-TNF and infliximab all with varying degrees of success. History
In 1981, Malleson et al. reported a family that had autosomal dominant synovitis, camptodactyly, and iridocyclitis. One member died of granulomatous arteritis of the heart and aorta. In 1982, Rotenstein reported a family with granulomatous arteritis, rash, iritis, and arthritis transmitted as an autosomal dominant trait over three generations.In 1985, Edward Blau, a pediatrician in Marshfield, Wisconsin, reported a family that over four generations had granulomatous inflammation of the skin, eyes and joints. The condition was transmitted as an autosomal dominant trait.