Objective: To determine the prevalence and type of histological abnormalities in duodenal mucosa associated with Giardia lamblia in children who undergo esophago-gastroduodenoscopy.
Materials and methods: Duodenal biopsies containing G lamblia were retrieved from all paediatric patients who had undergone endoscopy in our centre in the last 20 years. These biopsies were scored for histological abnormalities by a single pathologist using a semiquantative scale and staged according to the Marsh criteria. In those with a Marsh stage above 0, the presence of coeliac disease was investigated.
Results: After excluding all patients with concomitant coeliac disease, 4 out of 32 (13%) patients had a biopsy showing crypt hyperplasia and 1 out of 32 (3%) had partial villous atrophy. No intraepithelial lymphocytosis was found. In our cohort, 2 patients with giardiasis and mild histological abnormalities were diagnosed with coeliac disease only after a repeated endoscopy and serology were performed; in 1 of them after a delay of 5 years. Other histological abnormalities frequently observed were increased eosinophilic infiltration of the lamina propria (35%) and lymph follicle formation (35%). Infiltration of neutrophilic and eosinophilic granulocytes in the epithelial layer was observed less frequently (16% and 9%, respectively).
Conclusions: Villous atrophy, intraepithelial lymphocytosis and/or crypt hyperplasia are rare in children with giardiasis who undergo esophagogastroduodenoscopy. Therefore, other causes, particularly coeliac disease, should always be suspected. This study, however, suggests that giardiasis can cause chronic mucosal inflammation, often of an eosinophilic nature, in these children.