Background
- Small, thin, white nematode
- Adult females are 9 to 12 mm long, and adult males are 3 to 5 mm long
- Spread by fecal-oral route
- More common in preschool and school-aged children, institutionalized people, and household contacts of an index case
Clinical Manifestations
- Pruritus ani, or itching around the anus
- Excoriations can become secondarily infected
Diagnosis
- Stool microscopy may miss the eggs, since they are deposited outside the colon
- Diagnostic test of choice is the scotch tape test
- in the morning, before washing or pooping
- Press a piece of scotch tape about 2 x 10 cm against the anal and perianal regions several times
- Stick the tape onto a slide
- Microscopy can confirm the diagnosis
- Premade kits are available from labs and pharmacies
Management
- Antihelminthics:
- Albendazole 200-400 mg p.o. once, repeated at 2 weeks
- Pyrantel pamoate 10 mg/kg (max 1 g) p.o. once, repeated at 2 weeks
- Mebendazole 100-200 mg p.o. once, repeated at 2 weeks
- Others:
- Pyrvinium embonate 5 mg/kg (max 400 mg) p.o. once, repeated at 2 to 4 weeks
- For urogenital infections only: ivermectin 200 mcg/kg p.o. once, repeated at 2 to 4 weeks
- For chronic infections, the doses may need to be repeated every 2 weeks for up to 4 months
- Non-pharmacologic management should include handwashing and frequent changing and washing of underwear, pajamas, and bedsheets in order to prevent reinfection or transmission to other household members
