Whipple's disease: a granulomatous masquerader.

Whipple's disease is a multisystemic infection that affects middle-aged white men. It typically presents with fever, polyarthritis, diarrhea, steatorrhea, and weight loss. Many other systems can be involved, however, including the central nervous system, heart, lymphatics, lungs, bone marrow, and skin. Recent work has demonstrated the causative organism to be a complex bacteria, Tropheryma whipplei. The diagnosis is established most securely by periodic acid-Schiff staining of foamy monocyte-macrophages in biopsy tissue and body fluids, by electron microscopy, which reveals bacilli within membrane-bound vesicles, and by molecular amplification techniques using polymerase chain reaction of tissues and body fluids. The differential diagnosis includes chronic multisystemic infections and granulomatous disorders, because Whipple's disease is a fascinating blend of both. The condition can resemble sarcoidosis and mycobacterial disease and fungal, protozoal, and bacillary infections. Earlier diagnosis leads to earlier treatment and hopefully the prevention of chronic disabling complications and needless mortality from this once uniformly fatal condition.