1523 Unintended Discovery of Enterobius vermicularis During Colonoscopy: An Uncommon Visualization

Abstract

INTRODUCTION: Enterobius vermicularis (pinworm) is the most common helminthic infection in the United States with an estimated prevalence of nearly 40 million people. Transmission of E. vermicularis occurs when its infective eggs, carried on contaminated hands, food, or environmental surfaces, are ingested. The eggs travel to the jejunum and hatch, maturing throughout the remainder of the gastrointestinal tract, until they reach their residence in the cecum. Females exit through the rectum and lay their eggs on the perianal skin. Though most infections are clinically silent; occasionally patients present with perianal itching, sleeplessness, hyperactivity, weight loss, abdominal pain and/or vomiting. Diagnosis is classically made by collecting the characteristic eggs from the perianal region using an adhesive coated surface and viewing the eggs microscopically. Here we present an unusual diagnostic finding of incidental pinworms during colonoscopy. CASE DESCRIPTION/METHODS: A 36-year-old male was admitted with a three-day history of bright red blood per rectum and an intermittent history of melena over the past six months. History was remarkable for active alcohol abuse and alcoholic Childs A cirrhosis. On examination, the patient was hemodynamically stable, abdomen was soft and non-tender, rectal exam was without blood. Patient underwent upper endoscopy and colonoscopy for bleeding site identification. During colonoscopy a white serpiginous organism was found attached to the mucosa of the ascending colon (Figures 1 and 2). It was actively moving around over the colonic mucosa. The specimen was collected, and after pathology it was confirmed that the parasite was E. vermicularis. The remainder of the endoscopic investigation revealed both large esophageal varices and large internal hemorrhoids as likely culprits for the gastrointestinal bleed. DISCUSSION: Direct visualization of pinworm eggs collected from the perianal region of suspected infected individuals has been essential to the diagnosis of intestinal parasite infections. Routine screening for pinworms in asymptomatic patients is not standard practice. Nevertheless, as an increasing number of colonoscopies are performed each year, we may encounter more incidentally diagnosed pinworm infections.