Sarcoidosis

Abstract Sarcoidosis is an antigen‐mediated disease of unknown aetiology characterised by the presence of non‐caseating epithelioid cell granulomas in multiple organs. It involves mainly the lungs, mediastinal and peripheral lymph nodes, eyes and skin. Less frequent but usually severe manifestations can occur in the liver, spleen, central nervous system, heart, upper respiratory tract and bones. Cutaneous lesions of sarcoidosis may be specific, showing histopathologically sarcoid granulomas, or non‐specific, mainly erythema nodosum. Cutaneous lesions are frequently the presentation of the disease and skin biopsy enables early diagnosis. Moreover, some types of lesions have prognostic significance and may help to predict the outcome of the systemic disease.