Sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. The available evidence suggests that the disease results from an exposure of genetically susceptible hosts to specific and persistent environmental and occupational agents, which causes a heightened innate immune response in the involved organs leading to granuloma formation. Sarcoidosis usually presents with bilateral hilar lymphadenopathy, pulmonary, cutaneous, and ocular involvement, although any organ can be affected. Although they are less frequent, neurosarcoidosis and cardiac sarcoidosis require a special consideration. The diagnosis is based on a compatible clinical and radiological picture, demonstration of noncaseating granulomas with negative cultures for mycobacteria and fungus, and exclusion of other granulomatous diseases. The finding of granuloma at biopsy is not specific for sarcoidosis. The differential diagnosis of granulomatous diseases varies according to the involved organ. Tuberculosis and sarcoid reaction secondary to cancer should be excluded. In general, an acute onset, particularly Löfgren’s syndrome, has a good prognosis, while an insidious presentation heralds a chronic disease. A significant proportion of patients with sarcoidosis follows a spontaneous resolution without treatment. Corticosteroids should be administered when symptomatic and severe and progressive disease involves major organs, such as lungs, eyes, heart, and central nervous system. Several drugs, such as methotrexate, hydroxychloroquine, and infliximab, may be useful as alternative therapies in cases refractory to corticosteroid treatment.