The gold standard for diagnosis of Whipple disease is a duodenal biopsy that demonstrates a periodic acid–Schiff (PAS)-positive bacillus in macrophages within intestinal villi. A PCR analysis of peripheral blood and vitreous may show T whipplei DNA and confirm the diagnosis. Culturing of T whipplei is difficult but possible. The differential diagnosis of uveitis associated with Whipple disease includes diseases that can cause retinal vasculitis with multisystem involvement, including sarcoidosis, SLE, polyarteritis nodosa, and Behçet disease. Primary vitreoretinal lymphoma should also be considered in elderly individuals with significant vitreal infiltration.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.