Sarcoidosis, early-onset

Early-onset sarcoidosis (EOS) is a special subtype of sarcoidosis, a systematic inflammatory disease with unknown etiology. It occurs in children younger than 4 years of age and is characterized by a distinct triad of skin, joint, and eye disorders without apparent pulmonary involvement. Mutations in the gene encoding NOD2 in humans have been associated with EOS. NOD2 is an intracellular microbial sensor of the innate immune system that can act as a potent activator and regulator of inflammation.