Enterobius

(Redirected from Pinworm)

Background

Enterobious vermicularis life cycle.
  • Colloquially known as Pinworm (United States), Treadworm (UK and Australia) or Seatworm
  • Worldwide distribution
  • Risk factors (prevalence can reach up to 50% in these populations):
    • Age under 18
    • Institutionalized
    • Cohabitation with infected individual
  • Humans only known reservoir
  • Transmitted by fecal-oral route
  • Can survive outside of body for up to 3 weeks

Clinical Features

Two pinworms next to a ruler: The markings are 1 mm apart.

Differential Diagnosis

  • Idiopathic pruritus ani
  • Rectal tenesmus

Helminth infections

Cestodes (Tapeworms)

Trematodes (Flukes)

Nematodes (Roundworms)

Evaluation

  • Tape test
    • Most common
    • Touch transparent tape to the perianal region and examine for eggs under the microscope
  • Can also test by examining scrapings under patient's fingernails or examining perianal region 2-3 hours after patient falls asleep
  • Stool analysis does not work because of low egg burden in stool

Management

Treatment targeted against Enterobius vermicularis; All family members should be treated at the same time

Adult

  • Mebendazole 100mg PO once, THEN repeat in 2 weeks OR
    • Okay during breastfeeding[1]
  • Albendazole 400mg PO once, THEN repeat in 2 weeks OR
  • Pyrantel Pamoate (Pin-x) 11mg/kg (max 1g), THEN repeat in 2 weeks
    • First choice for pregnant patients
      • Treat in pregnancy only if the infection is compromising the pregnancy (i.e. weight loss, sleeplessness); withhold until the 3rd trimester if possible.[2]

Pediatric

  • 2 years or older:
  • <2 years

Prevention

  • Carefully hand washing after using the toilet, and before and after eating
  • Thoroughly launder all bedding, clothing, and toys to destroy any lingering eggs
  • Launder all bedding every 3-7 days for three weeks
  • Wash underwear and pajamas daily for two weeks

Disposition

  • Outpatient treatment

External Links

See Also

References

  1. CDC Resources for Health Professionals. Accessed 5/9/2021. https://www.cdc.gov/parasites/pinworm/health_professionals/index.html
  2. CDC Resources for Health Professionals. Accessed 5/9/2021. https://www.cdc.gov/parasites/pinworm/health_professionals/index.html