Surprising finding on colonoscopy
While looking for the cause of our patient’s intermittent rectal bleeding, we discovered something else entirely.
The whipworm is found in the southeastern states, but is more common in immigrants and migrant workers. A portion of the helminth burrows into the intestinal wall and may cause mild anemia, diarrhea, symptoms of inflammatory bowel disease, or rectal prolapse.1
Threadworms are prevalent throughout the tropical eastern hemisphere and are most commonly found in immigrants. Larvae penetrate the skin, migrate through the bloodstream to the lungs, and are coughed up and swallowed. The filariform stage penetrates the anal skin or intestinal mucosa, perpetuating infection, which may persist for 40 years—long after the patient has immigrated. Clinical presentation includes pruritus ani, pneumonia, abdominal cramping, and colitis.1
Hookworms have a similar geographic distribution to the threadworm. Necator americanus is the most prevalent hookworm in the United States, found in the southeast. Like the threadworm, larvae penetrate the skin, usually the feet, causing a rash. They migrate to the lungs, where they are coughed up and swallowed. In the intestines, they consume blood and cause iron deficiency anemia. Other symptoms include fatigue, failure to thrive, and depression. These worms may persist for 15 years.1
Some patients have itching, others are asymptomatic
The classic presentation of pinworm infection includes perianal itching that is worse at night and is associated with sleep disturbances, which our patient experienced. However, the vast majority of patients are asymptomatic, leading to underdiagnosis of the infection.2 This patient’s only complaint was intermittent rectal bleeding, which was likely due to his hemorrhoids.
More common presentations include abdominal pain, anorexia, weight loss, and diarrhea. However, case reports have described a variety of presentations, some with significant morbidity and mortality, often related to migration of the worms into the genitourinary tract and pelvic cavity.3 These include vulvovaginitis, pelvic inflammatory disease, pelvic abscesses and granulomas, urinary tract infections, prostatitis, epididymitis, appendicitis, enterocolitis, and bowel obstruction.3,5-7Physical exam findings may include perianal excoriation, with or without bacterial superinfection.
