Enterobius vermicularis, the small human pinworm: a chronic infestation diagnosed by Pillcam. Incidental observation on Capsule Endoscopy

Description

A 35-year-old male presented complaints of cramps, diarrhoea, lower abdominal pain, mild iron-deficiency anaemia but without weight loss, nausea, vomiting or gastrointestinal bleeding. Gastroscopy, colonoscopy, small bowel follow-through, laboratory data and faecal microscopy were normal. At capsule endoscopy, multiple small live worms compatible with Enterobius vermicularis were identified. They had the appearance of pinworms (figure 1 and video), approximately 4-mm long and swam in the distal jejunum and ileum. The mucosa throughout small bowel was endoscopically normal. Histopathology of the worms confirmed it to be an E vermicularis. At the time of follow-up, after treatment with albendazole 400 mg once a day for 3 days and iron supplements symptoms had completely disappeared. The adult worms are small; the females are larger than the males and typically range from 8 to 13 mm. They live mainly in the caecum and have been seen in the appendix. The eggs of these warms are spread by the faecal-oral route to both the original host and new hosts. Once the eggs are ingested, they hatch in the duodenum and the larvae mature as they migrate to the colon over a few weeks. The most cases of E vermicularis are asymptomatic. The main symptom is perianal itching and can be due to mechanical stimulation, irritation or allergic manifestations. The diagnosis is generally made by the “Scotch tape” or “cellophane tape” test. The sensitivity of the test is 90%. This test should be done as the first thing in the morning, before a shower or bath and because E vermicularis is easily spread throughout households.

Figure 1 and video.

E vermicularis swimming in the colon.

Video 1.

Download video file ^{(382.1KB, flv)}

DOI: 10.1136/bcr.09.2009.2258v1