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A 27-year-old Caucasian male presented with a one-month history of diarrhoea, severe abdominal cramping, heartburn and weight loss. The symptoms began right after breakfast in the morning and continued with 3–4 watery stools throughout the day, but none during the night. Spicy foods, alcoholic beverages and excessive water intake seemed to exacerbate the pain, but soda seemed to alleviate it. The patient denied use of antibiotics, antispasmodics, or antihypertensive drugs, and drank minimal milk. The patient denied any recent international travel or contact with diapers or ill persons but confirmed that the symptoms started about a week after a river trip. There was no known family history of GI disease. Endoscopically, the oesophageal, gastric, small bowel and colonic mucosa appeared normal. Multiple cold forceps biopsies were performed for histology in the lower third of the oesophagus, second part of the duodenum, terminal ileum (TI) and random colon. Initial morphological examination of the duodenal biopsy showed variable villous blunting and increased intraepithelial lymphocytes and neutrophils (figure 1). Serum t-transglutaminase immunoglobin A and immunoglobin G antibodies obtained during the course of his illness were negative.
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Although coeliac disease (CD) can suddenly arise in an adult patient and cause villous atrophy of the duodenum, tests in the coeliac panel were negative. Because the patient reported taking a recent river trip, an infectious aetiology should be considered. Morphological examination of biopsies from the TI, colon and duodenum showed giardiasis (figure 2A–C). Following diagnosis, the patient began treatment with metronidazole (Flagyl), which significantly improved his symptoms.
CD is estimated to affect 0.3%–1% of the Western world, causing small-bowel malabsorption after ingestion of gluten,1 the gold standard of which is determined by duodenal biopsy showing villous blunting and intraepithelial lymphocytosis. CD, however, is not the only cause of villous blunting.2 Other food intolerances or allergies, parasitosis,3 reaction to medications4 and various immunodeficient syndromes should also be considered.1
In Europe, the prevalence of Giardia on routine duodenal biopsy is 0.45% (CI 0.16 to 0.74%).5 Giarda lamblia, the most common intestinal protozoa worldwide, does not usually cause more significant morphological alterations in the mucosa than mildly increased inflammation. However, partial or complete villous blunting and crypt hyperplasia mimicking CD have been reported.6 This report illustrates an unusual distribution of Giardia within the GI tract and serves as a reminder to clinicians and specifically pathologists to consider parasites in the setting of duodenal villous blunting.
Contributors DJL contributed to the design of the study, drafting the manuscript, interpretation of the pathology, and final approval of the article. JJW contributed to the design of the study, drafting the manuscript, obtaining the patient's written consent, interpretation of the gastroenterology, and final approval of the article. JAN contributed to the design of the study, drafting the manuscript, administrative tasks and final approval of the article.
Competing interests None.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
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