Sarcoidosis is a systemic disease characterized by non-necrotizing granulomata and manifestations in almost any organ. Diagnosis relies on the exclusion of other granulomatous disorders and a compatible pattern of symptoms and clinical findings. Competing differential diagnoses encompass infectious, autoaggressive, and occupational disorders. Inflammatory lesions and granulomata may undergo spontaneous resolution or persist in chronic disease with eventual fibrosis and permanent organ damage. Immunological disease mechanisms are linked to severe derangements of the cytokine network. These pathomechanisms depend on a genetic background. Many variant genes define sarcoidosis susceptibility and genotype-phenotype relationships are elucidated which will allow individualized therapy in the near future. In systemic resolution or under prednisolone therapy of symptomatic disease proinflammatory cytokines are downregulated and histological lesions may completely vanish. Corticosteroid-resistant disease, however, requires treatment with an immunosuppressive regimen consisting of prednisolone and an immunosuppressive agent or anti-tumour necrosis factor (TNF) monoclonal antibodies.
Disclosure of Interest None declared