One case of Giardia lamblia-associated arthritis in a 23 year-old woman.

Giardia lamblia, a gastrointestinal protozoan, is one of the most common disease-causing parasites in the world. Giardiasis is primarily encountered in areas with poor sanitation, but it is also seen in more developed countries. A possible sequela of Giardia infections of the bowel is reactive arthritis or synovitis. Few reports of synovitis secondary to giardiasis exist in the literature. Arthropathy secondary to giardiasis is uncommon, but may be underdiagnosed. We present a 23 year-old woman who had polyarthritis after Giardia lamblia infestation. The synovitis subsided with treatment of the giardiasis with metronidazole. The diagnosis of Giardia synovitis should be suspected by the presence of Giardia cysts in the stool. Although uncommon, giardiasis can cause severe synovitis that may be confused with a septic joint. (Korean J Med 61:82-85, 2001)