Eosinophilic vasculitis: a rare presentation of Whipple's disease.

Whipple's disease is a multisystem infectious disease caused by the bacterium Tropheryma whippelii. A case with an unusual presentation is reported. A 66-year-old man presented with a febrile vasculitic rash on his forearms. An extensive rheumatological, hematological and infectious workup gave negative results, apart from mild anemia and eosinophilia. An abdominal computed tomography revealed a retroperitoneal lymphadenopathy, and a skin biopsy revealed an eosinophilic vasculitis. This diverted the work toward ruling out a lymphoma or a vasculitic process. A lymph node biopsy was then performed and showed a diffuse neutrophilic inflammation with abundant foamy macrophages, fat necrosis and lipogranuloma formation. These findings were considered to be nonspecific and no further pathological investigation was carried out. After a course of corticosteroids, diarrhea and weight loss predominated and subsequently a diagnosis of Whipple's disease was confirmed on a small-bowel biopsy. Lymph node involvement was then confirmed on re-evaluation using the appropriate stains.