Pinworm Treatment
For typical enterobiasis (pinworm infection), treat with a single oral dose of either albendazole 400 mg or mebendazole 100 mg, repeated in 2 weeks, which applies to both children and adults. 1, 2
First-Line Medication Options
Both medications are equally effective and safe across all age groups: 1
- Albendazole 400 mg as a single oral dose, repeated in 2 weeks 1, 2
- Mebendazole 100 mg as a single oral dose, repeated in 2 weeks 1, 2
The tablet may be chewed, swallowed, or crushed and mixed with food. 2
Why Two Doses Are Essential
The second dose at 2 weeks is critical to eradicate any newly hatched worms from eggs that survived the initial treatment, as these medications are adulticidal and ovicidal but eggs may still be present in the environment. 1, 3
Clinical Context
Recognizing Pinworm Infection
- Nocturnal perianal itching is the hallmark symptom 1, 3
- 30-40% of infected patients are completely asymptomatic 1, 3
- Other presentations include irritability, weight loss, diarrhea, abdominal pain 1
- In girls, vaginal discharge may occur from female genital tract colonization 1
Diagnostic Approach
The cellophane tape test (sticky side applied to perianal skin in the morning before bathing) is the preferred diagnostic method, as pinworms and eggs are not usually passed in stool. 1, 3 A single test has only 50% sensitivity, but three tests on different mornings increase sensitivity to approximately 90%. 3
Treatment of Household Members
Treat all household members simultaneously, especially with multiple or repeated symptomatic infections, as reinfection is extremely common. 3, 4 The involvement of all persons living in the household, including sexual partners, is a prerequisite to lasting treatment success. 4
Managing Treatment Failure
True treatment failure is rare—persistent symptoms usually indicate reinfection rather than medication resistance. 1 If symptoms persist after treatment:
- Consider reinfection from untreated household contacts 3
- Reassess hygiene measures 3
- A second course of treatment may be given if the patient is not cured three weeks after initial treatment 2
Critical Hygiene Measures
Prevention of reinfection requires: 3
- Frequent handwashing, especially after bowel movements and before meals
- Clipping fingernails short
- Avoiding finger-sucking, nail-biting, and scratching the anogenital area
- Daily morning bathing to remove eggs deposited overnight
Special Populations
Children
The same standardized dose applies to children of all ages, including 2-year-olds: albendazole 400 mg or mebendazole 100 mg. 1
Pregnancy
For pregnant women, pyrantel pamoate is preferred over mebendazole and albendazole due to safety considerations. 3
Common Pitfalls to Avoid
- Don't rely on stool examination for diagnosis—pinworms and eggs are not usually passed in stool 1
- Don't treat the patient alone—failure to treat household contacts is the most common cause of apparent treatment failure 3, 4
- Don't skip the second dose—the 2-week repeat is essential for eradication 1, 2
- Don't assume treatment failure—recurrence almost always represents reinfection, not resistance 1
Monitoring
No special procedures such as fasting or purging are required. 2 If using albendazole for more than 14 days (which would be unusual for pinworm but relevant for other helminthic infections), monitor for hepatotoxicity and leukopenia. 1