Blau syndrome is a rare, monogenic, autoinflammatory disorder resulting from heterozygous gain-of-function mutations in the NOD2 (nucleotide-binding oligomerization domain 2) gene, a cytosolic pattern-recognition molecule that leads to constitutive activation of nuclear factor–κB (NF-κB) signaling. The classic triad includes granulomatous dermatitis, uveitis, and arthritis, but some patients develop incomplete manifestations.1 Clinically, lichen scrofulosorum must be ruled out with a negative finding on tuberculin test, since these entities are histologically and clinically indistinguishable. Treatment with systemic immunosuppressive agents is directed toward controlling ocular and joint inflammation, and skin disease often, but not always, responds to these therapies. We describe 2 patients with Blau syndrome, whose dermatologic disease remained quiescent with use of oral erythromycin. These outcomes suggest that it may be a novel therapy for patients with refractory skin disease or mild systemic disease.