There are multiple causes of uveitis. The main reason you are being seen by a rheumatologist is to be evaluated for a potential systemic autoimmune condition. Uveitis causes are categorized into different subsets: infection vs autoimmune conditions (systemic autoimmune condition or other immune-related conditions) vs syndromes isolated strictly to the eye. About 40% of patients may have uveitis related to an autoimmune condition. Interestingly, in about 30% of patients, there is no identifiable cause so we then classify it as idiopathic uveitis.
There are numerous infectious causes of uveitis, among which include bacterial and spirochetal diseases (among which includes tuberculosis, syphilis), viral diseases (among which includes herpes virus, cytomegalovirus – CMV, West Nile virus), fungal infections, and parasitic infections (for instance, toxoplasmosis). We have to obtain blood samples to evaluate for exposures to these organisms.