Sarcoidosis

Abstract

Sarcoidosis is a chronic inflammatory disease of unknown etiology characterized by the formation of noncaseating epithelioid granuloma in multiple systemic organs such as lung, lymph nodes, eyes, or skin. The other organs including heart, liver, bones, salivary glands, nervous, or muscles are also affected but the incidences are much less. Among all sarcoidosis patients, about 40–50% of the patients develop ocular complications including granulomatous uveitis (Obenauf et al. 1978; Jabs and Johns 1986; Ohara et al. 1992). The ocular symptoms such as photophobia, blurred vision, or floaters, often appear as the first symptoms of sarcoidosis. Although the etiology of sarcoidosis is not known yet, systemic cellular immune responses against certain microbes such as Mycobacterium tuberculosis (Fang et al. 2016), Propionibacterium acnes (Ishige et al. 2005; Negi et al. 2012), or mumps virus (Uzun et al. 2004) are hypothesized to be the causative antigen to form granulomas in sarcoidosis. Most affected ages by sarcoidosis distribute between the third to fifth decade of life in both genders, and elderly women are also affected (Silver and Messner 1994). Sarcoidosis is currently the most frequent cause of uveitis in Japan (Ohguro et al. 2012), but it is not the case in other countries including neighboring Asian countries. In general, African American, Asian, and South Americans are often affected by sarcoidosis, while Caucasian people are less affected.