What is the recommended treatment for pinworms (Enterobius vermicularis)?

Treatment of Pinworms (Enterobius vermicularis)

The recommended first-line treatment for pinworm infection is a single dose of albendazole 400 mg or mebendazole 100 mg, with a repeat dose after 2 weeks to prevent reinfection. 1

Diagnosis

Before treatment, proper diagnosis is essential:

• The most accurate diagnostic method is the "cellophane tape test" (also called "sellotape test") performed by placing the sticky side of clear tape on the perianal skin in the morning before bathing or defecation, then examining it under a microscope for ova 1, 2
• A single test has approximately 50% sensitivity, but performing the test on three consecutive mornings increases sensitivity to about 90% 2
• Direct visualization of adult worms in the perianal area is also diagnostic
• Standard stool examination is not recommended as pinworms and eggs are not typically passed in stool 2

Treatment Options

First-line medications:

1. Albendazole 400 mg as a single dose 1

   • Highly effective with 100% cure rate reported 3
   • Both adulticidal and ovicidal 2
   • Well-tolerated with minimal side effects 4

2. Mebendazole 100 mg as a single dose 1, 5

   • 95% cure rate for pinworm infections 5
   • Also both adulticidal and ovicidal 2
   • Available as chewable tablets that may be swallowed whole, chewed, or crushed and mixed with food 5

3. Pyrantel pamoate 11 mg/kg (maximum 1 g) as a single dose 2

   • Alternative option with 96.3% cure rate 6
   • Only adulticidal (not ovicidal) 2
   • Preferred option for pregnant women 2

Treatment Protocol

1. Administer single dose of chosen medication
2. Repeat the same dose in 2 weeks to kill newly hatched worms 2
3. Consider treating all household members simultaneously, especially with multiple or repeated infections 2

Prevention of Reinfection

Pinworm reinfection is common due to the short life cycle of the parasite and ease of autoinfection. Implement these measures to prevent reinfection:

• Frequent handwashing, especially after using the toilet and before eating
• Regular cleaning of toilet seats and bathroom fixtures
• Changing and washing underwear, pajamas, and bed linens frequently
• Keeping fingernails short and discouraging nail-biting and finger-sucking
• Daily showering or bathing in the morning to remove eggs deposited overnight
• Avoiding scratching the perianal area 2

Special Considerations

• Children: Same dosing as adults for all recommended medications 5
• Pregnant women: Pyrantel pamoate is preferred over mebendazole and albendazole 2
• Household treatment: Consider treating all household members simultaneously to prevent reinfection cycles 2
• Institutional settings: In schools or care facilities, coordinated treatment may be necessary to control outbreaks

Despite effective medication, recurrences are common due to the short life span of adult pinworms and ease of reinfection, particularly through autoinfection. Combining medication with good hygiene practices provides the most effective approach to treatment and prevention.