Whipple's disease (WD) is known as an infrequent, systemic, chronic infection caused by the actinomycete Tropherima whipplei (T. whipplei). The disease is frequently characterized by a long prodromal and protean extra-intestinal phase, which often causes misdiagnosis and inappropriate treatments. Herein, we describe the case a 62-year-old man with a histological diagnosis of WD established when oral steroid treatment was started due to rheumatic manifestations, triggering intestinal symptoms. Systematic review of the literature was performed to include studies where WD was eventually diagnosed on duodenal biopsies. Three patients' subgroups were identified according to the clinical presentation.