Non‐Necrotizing Granulomatous Dermatitis in an Infant: Infantile Sarcoidosis or Initial Manifestation of Blau Syndrome?

A 14‐month‐old, otherwise healthy boy presented with a six‐month history of an asymptomatic eruption that began on the face and progressively involved most of the cutaneous surface. The patient’s father and paternal grandfather both had a history of chronic uveitis that began during adolescence. Physical examination revealed numerous 1‐ to 2‐mm, red‐brown, flat‐topped papules on the trunk, extremities, and face. The serum ACE level was elevated. Other pertinent laboratory tests and a CXR were normal. The tuberculin skin test was negative. There were no signs of arthritis or uveitis. A punch biopsy revealed a perifollicular, perieccrine, superficial, and deep perivascular non‐necrotizing granulomatous infiltrate, admixed with a few neutrophils. No polarizable material was present. AFB, Fite, and Grocott stains were negative for organisms. A clinico‐pathologic diagnosis of sarcoidosis was initially rendered. Given the family history, a diagnosis of Blau syndrome, a rare autosomal dominant disorder caused by mutations in the CARD15 gene and characterized by arthritis, uveitis, and a non‐caseating granulomatous dermatitis, is explored. Blau syndrome has substantial overlap with early‐onset sarcoidosis and is thought to represent the familial form of the disease. Analysis of the CARD15 gene is in progress for the patient and his family.