Tattoo-associated uveitis with or without systemic sarcoidosis: a comparative review of the literature

Sarcoidosis is a systemic disease of unknown aetiology characterized by the presence of non-caseating epithelioid cell granulomas in multiple organs, mainly the lungs and the lymphatic system. It is also one of the leading cause of inflammatory eye diseases. For the past 70 years, sarcoidal granulomas on tattoos and permanent make-up have been documented. They can be the first and sometimes unique cutaneous manifestation of systemic sarcoidosis. A few cases of sarcoidosis with uveitis and granulomatous reactions within tattoos have been described. However, since the end 60s, a singular entity has been reported associating isolated uveitis with granulomatous cutaneous reaction restricted to tattoos in the notable absence of systemic sarcoidosis. It remains unclear whether this entity must be distinguished from sarcoidosis. This review summarizes the currently available data on this topic and compares cases of sarcoidosis with granulomatous tattoo reaction and uveitis to the cases without notable sarcoidosis. We propose the acronym TAGU (TAttoo Granulomas with Uveitis) as an exclusion diagnosis that emcompasses the patients for whom we fail to find any sarcoidosis or other causes after extensive investigation.