Chronic Diarrhea and Abdominal Pain — Pin the Pinworm

1Cleveland Clinic, Cleveland, OH

Meeting: Hospital Medicine 2007, May 23-25, Dallas, Texas

Abstract number: 146

Case Presentation:

An 84‐year‐old female patient from an assisted‐living facility (ALF) was admitted with complaints of abdominal pain and diarrhea (7‐8 episodes/day, watery, non‐foul‐smelling) for 2 months. She denied nausea, vomiting, fever, chills, anal pruritus, melena, or rectal bleeding. She also denied recent travel, hospitalizations, antibiotic use, or exposure to sick contacts. The results of both outpatient and inpatient workups of stool for Clostridium difficile, fat, blood, ova, and parasites, culture, and sensitivity were negative. Computed tomography of the abdomen/pelvis was unremarkable Outpatient courses of loperamide and Lomotil were unsuccessful. She was admitted for a further workup, including a possible GI consult and colonoscopy. The scotch tape test was positive for Enterobius vermicularis (pinworm) infection. She was given a dose of albendazole. Her diarrhea and abdominal pain resolved, and she remained symptom free on discharge.


Enterobius vermicularis is the most common helminthic infection in the United States, affecting about 20‐40 million people in the United States and about 200 million people worldwide. Infection occurs in all socioeconomic groups. It occurs more commonly in closed, crowded living conditions. Humans are the only natural host for this parasite, and transmission occurs via the feco‐oral route or via airborne eggs. Most infections with E. vermicularis are asymptomatic. A review of the literature showed the pinworm to be the causative agent of cases of eosinophilic enterocolitis, appendicitis, vulvovaginitis, pelvic inflammatory diseases, conditions mimicking inflammatory bowel disorders, perianal abscesses, and perianal granulomas, and there were several case reports of colitis secondary to E. vermicularis in which patients presented with pain, rectal bleeding, fever, nausea, vomiting, and diarrhea with symptoms resolving with antiparasitic therapy alone. In a retrospective study, the symptom profile of patients with confirmed E. vermiculariswas abdominal pain (73%), rectal bleeding (62%), chronic diarrhea (50%), and weight loss (42%). The confirmatory scotch tape test is simple and quick. Asingle dose of albendazole repeated after 2 weeks achieves cure rates close to 100%.


E. vermicularis is generally considered a blameless nematode that at the most causes perianal pruritus. Although the pin‐worm's entire life cycle is in the human GI tract, gastrointestinal symptoms have seldom been reported. But the frequency of gastrointestinal symptoms is probably higher than previously suspected and probably underreported. Given the increasing number of nursing home and ALF patients seen in the hospital, it is important for a hospitalist early on to consider pinworm as important in a differential diagnosis for patients presenting with symptoms of colitis, even in the absence of anal pruritis. This avoids an unnecessary and expensive workup, decreases length of stay, and definitely improves patient satisfaction.

Author Disclosure:

A. Rajamanickam, None; A. Usmani, None; S. Suri, None.

To cite this abstract:

Rajamanickam A, Usmani A, Suri S. Chronic Diarrhea and Abdominal Pain — Pin the Pinworm. Abstract published at Hospital Medicine 2007, May 23-25, Dallas, Texas Abstract 146. Journal of Hospital Medicine. 2007; 2 (suppl 2). Accessed April 3, 2020.

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