Presentation at IAP - By Dr. Sanjay Pai

Consider Amoebiasis in Face of Supposed Tuberculosis or Inflammatory Bowel Disease: Presented at IAP

MONTREAL, CANADA -- September 19, 2006 -- Periodic Acid Schiff (PAS) staining can help differentiate amebiasis from inflammatory bowel disease (IBD) and tuberculosis.

All three of these conditions can have similar clinical and endoscopic manifestations but appropriate treatment differs dramatically.

"It is absolutely crucial to make the distinction because, for the treatment of inflammatory bowel disease, you use steroids," said Sanjay Pai, MD, a consultant pathologist and head of Manipal Hospital Diagnostic Services, Bangalore, India.

"If you give steroids to someone with amebiasis, [the colon is] going to perforate, and he's going to die. Alternatively he might be sent in for major surgery -- removing the colon -- whereas the treatment for amebiasis is just metronidazole for about a week or so," Dr. Pai said during his poster presentation on September 18^th at the 26^th International Congress of the International Academy of Pathology (IAP).

Over a 3-year period, Dr. Pai identified 9 individuals with amebiasis whose endoscopic evaluations were considered suggestive of IBD or tuberculosis. Chief symptoms included diarrhea, blood in the stools, and rectal bleeding. Endoscopic evaluation revealed multiple deep ulcers with normal intervening mucosa.

"We have patients with endoscopic appearances that look just like inflammatory bowel disease," he said. "Because tuberculosis is extremely common in India, when the endoscopist sees this, he says, 'tuberculosis or inflammatory bowel disease.'"

The presence of trophozoites of entamoeba histolytica in the exudate was the only pathological feature that differentiated amebiasis from IBD or tuberculosis. These were only clearly visible using PAS staining, however. "You do a PAS and even a blind man can see this," said Dr. Pai. "It stands out."

Based on these findings, Dr. Pai says he has learned that, "when an endoscopist sends you a colonic biopsy and says I'm looking at tuberculosis or IBD, maybe there's a third differential."

While amebiasis is rare in Western countries, it occurs in the developing world, including South America, Africa, and large parts of Southeast Asia. With increased global travel, however, this could be a relevant diagnosis even in Westerners, particularly frequent travelers.