Whipple arthritis: diagnosis by molecular analysis of synovial fluid--current status of diagnosis and therapy.

Whipple's disease (WD) is an uncommon polysystem infectious disease. In the present report, we describe a patient who presented with a chronic illness consistent with WD and an avascular necrosis of the right hip joint. WD and its proposed causative bacillus, Tropheryma whippelii, was identified by molecular analysis (polymerase chain reaction) in bacterial DNA extracted from the synovial fluid. The diagnosis was additionally confirmed by upper gastrointestinal endoscopy and a small bowel biopsy with macrophages positive for periodic acid-Schiff reagent demonstrated by light and electron microscopy. This demonstrates that WD can be diagnosed without tissue biopsy. False diagnosis of the polymorphous signs and symptoms of WD can lead to invalidism and even death, whereas correct therapy leads to a cure in most cases. Thus, the current status of diagnosis and therapy is of key importance in the treatment of WD.