An Interesting Cause of Rectal Bleeding in an African Immigrant

Abstract

Question: A 30-year-old Sudanese-born man who emigrated to the United States 10 years ago with a past medical history of hepatitis B as well as recently treated Helicobacter pylori gastritis presented for outpatient follow-up for management of hepatitis B. His previous symptoms of heartburn and dyspepsia had improved with treatment of H pylori. He now complained of rectal bleeding with anal pruritus. He had no recent travel, no sick contacts, and had not started any new medications. On physical examination, he was afebrile with stable vital signs. He seemed well nourished. He had no scleral icterus. His abdominal examination was benign. He had no rash or jaundice. Rectal examination revealed no abnormalities. Complete blood count with differential revealed a white blood count of 3.1 K/μL with 6.1% eosinophils. Chemistry was normal. Liver function tests were unremarkable other than a stable total bilirubin of 1.8 g/dL. A flexible sigmoidoscopy (Figure A) was performed which revealed erythematous mucosa in the sigmoid colon, which was biopsied for pathologic examination (Figure B and C). What is the diagnosis? How should this patient be treated? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Tissue biopsy confirmed colonic mucosa with parasitic egg forms with granulomatous and eosinophilic response, concerning for Schistosoma mansoni. The patient was treated with praziquantel and had improvement in symptoms. Schistosomiasis is caused by a parasite that uses snails as intermediate hosts and humans as definitive hosts. It is endemic in parts of Africa, the Middle East, and Asia. Humans are infected through skin penetration in freshwater containing larvae. Most patients infected are asymptomatic. Acute infection in travelers can cause a localized dermatitis called “swimmer's itch” and a hypersensitivity syndrome known as Katayama fever. Those with this syndrome tend to present with symptoms similar to serum sickness and findings of lymphadenopathy and hepatosplenomegaly. Chronic manifestations in those living in endemic areas result from a granulomatous response to egg trapping in various organ systems, including the intestines, liver, bladder, and central nervous system. Examination of urine or feces for egg forms is the gold standard for diagnosis of active infection. Tissue biopsy may be required for diagnosis. Infected patients should be treated with praziquantel. Glucocorticoids should be used in patients with suspected Katayama fever and those with neurologic involvement. After treatment, urine or stool specimens should be assessed for cure.1Clerinx J. Van Gompel A. Schistosomiasis in travelers and migrants.Trav Med Infect Dis. 2011; 9: 6-24Crossref PubMed Scopus (92) Google Scholar It is important to have a high index of suspicion in immigrants and travelers for rarely encountered sources of pathology that may have been acquired outside the United States. Although it is unclear the exact duration of our patient's infection, he likely was infected while living in the Sudan.