Schistosomiasis with Duodenal Involvement Presenting as Irritable Bowel Syndrome in a 9-Year-Old Patient

Abstract

Abstract Introduction/Objective Schistosomiasis is extremely rare in the United States. Most patients diagnosed in the US have an international travel history or recently immigrated from endemic areas. We report a case of a 9-year-old boy who presented with a three-month history of daily abdominal pain, decreased appetite, weight loss, and microcytic anemia. The patient had alternating symptoms of constipation and diarrhea mimicking Irritable Bowel Syndrome (IBS). Methods CT scans showed distal sigmoid colon with wall thickening and hyperenhancement. Stool Helicobacter pylori antigen test was positive and hemoglobin levels were low (11 g/dL). The blood eosinophil count was initially within the normal range but was significantly elevated three months later (2,115 cells/µL). Esophagogastroduodenoscopy and colonoscopy were performed, which showed patchy areas of erythema and punctate bleeding within the descending and sigmoid colon. Results Gastrointestinal tract biopsies revealed focal, prominent eosinophilic infiltrates in the lamina propria. There were multifocal granulomas and fibrosis surrounding Schistosoma ova in the lamina propria and submucosa of duodenum, cecum, colon, and rectum. Acid-fast stain highlights the shell and spine of the ova. A retrospective chart review revealed that the patient had traveled to Yemen one month before the onset of symptoms. Schistosomiasis is among the top differentials for marked, sustained eosinophilia, especially with relevant travel history. Distortions caused by processing and sectioning can make speciation difficult on tissue sections. Acid-fast staining of the shell would favor S. mansoni over S. intercalatum; however, the S. intercalatum-S. hematobium hybrid also has an acid fast–positive shell. The duodenum is an uncommon location to find Schistosoma ova, which are usually found in the rectum and sigmoid colon. Conclusion The symptoms of gastrointestinal schistosomiasis may mimic IBS, and eosinophilia may initially be not evident as in this case. However, a high degree of suspicion is required in diagnosing schistosomiasis in patients from endemic areas.