What is the recommended treatment for a patient with a pinworm infection?

Treatment of Pinworm Infection

The recommended treatment for pinworm infection is a single oral dose of either albendazole 400 mg or mebendazole 100 mg, repeated in 2 weeks, with both medications showing equal efficacy and safety. 1

First-Line Medication Options

Both medications are endorsed by the American Academy of Pediatrics and have standardized dosing across all age groups: 1

• Albendazole 400 mg as a single oral dose, repeated in 2 weeks 1
• Mebendazole 100 mg as a single oral dose, repeated in 2 weeks 1, 2

The FDA-approved mebendazole formulation achieves a 95% cure rate for pinworm infection. 2 The tablet may be chewed, swallowed, or crushed and mixed with food. 2

Key Pharmacologic Differences

• Albendazole and mebendazole are both adulticidal (kill adult worms) and ovicidal (kill eggs) 3
• The two-week repeat dose is critical because it targets newly hatched worms from eggs that survived the initial treatment 1
• No special procedures such as fasting or purging are required 2

Treatment of Household Contacts

All household members should be treated simultaneously, especially when there are multiple or repeated symptomatic infections. 3 This approach is essential because:

• Reinfection is extremely common even with effective medication 3
• Autoinfection occurs readily through the fecal-oral route 3
• Treating only the symptomatic individual leads to rapid reinfection from untreated household members 4

Clinical Presentation to Recognize

The most common symptom is nocturnal perianal itching, though 30-40% of infected children are asymptomatic. 1 Other presentations include: 1

• Weight loss and irritability
• Diarrhea and abdominal pain
• Vaginal discharge in girls (from female genital tract colonization)

Diagnostic Confirmation

The cellophane tape test is the preferred diagnostic method, applied to the perianal skin in the morning before bathing. 1 Important diagnostic considerations:

• A single test has only 50% sensitivity, but three tests on different mornings increase sensitivity to approximately 90% 3
• Pinworms and eggs are not usually passed in stool, so stool examination is not recommended 1, 3

Management of Treatment Failure

Persistent symptoms after treatment almost always indicate reinfection rather than medication resistance. 1 If symptoms persist three weeks after treatment, a second course is advised. 2 Consider:

• Retreatment with the same medication 2
• Ensuring all household members were treated simultaneously 3
• Reinforcing hygiene measures (see below)

Essential Hygiene Measures

These non-pharmacologic interventions are critical to prevent reinfection: 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 of all ages (including 2-year-olds): Use the standard adult dose of albendazole 400 mg or mebendazole 100 mg 1
• Pregnant women: Pyrantel pamoate is preferred over albendazole and mebendazole 3

Monitoring for Prolonged Treatment

If treatment extends beyond 14 days (which is not typical for pinworm but may occur with other helminthic infections), monitor for hepatotoxicity and leukopenia. 1