Sarcoidosis: a Critical Review of History and Milestones.

Sarcoidosis is a chronic systemic disease of unknown origin and uncertain prognosis that most commonly affects young adults, and frequently presents with bilateral hilar lymphadenopathy, pulmonary infiltrates and ocular and skin lesions. The diagnosis is established when characteristic clinical-radiological features are supported by compatible histopathology of epithelioid cell granulomas, following exclusion of known causes of granulomatous inflammation. Indeed, sarcoidosis belongs to a large family of disorders that share granuloma formation as common denominator. Since its first description by Jonathan Hutchinson in 1869, sarcoidosis has generated enormous interest and considerable controversy. In Hutchinson's day, it was considered a dermatological condition, which gradually evolved into a multisystem disorder associated in the majority of cases with respiratory abnormalities. With time, it has also become clear that sarcoidosis occurs throughout the world, affecting individuals of both genders and all races, although its prevalence varies widely across ethnic and racial groups. In recent years, advances in different disciplines, particularly biochemistry, genetics, immunology and molecular biology, have improved dramatically our understanding of the disease. Yet, the critical questions regarding who gets sarcoidosis and whether it has an infectious origin remain unanswered. Sarcoidosis has a distinguished medical history that covers the last 150 years. Right from the time of seminal contributions by Hutchinson, Besnier and Boeck medical discussion on sarcoidosis has always been animated and to a certain extent emotional. Such discussions will inevitable continue until the true cause of the disease has been found, hopefully in the near future.