Pinworm infection is the most common worm infection in the United States, particularly among preschool-aged and school-aged children. These small parasitic roundworms spread easily among children, caregivers and household members. Some people have no noticeable symptoms, while others experience nighttime itching, restless sleep and skin irritation.
Pinworms can be treated with over-the-counter or prescription medicine. Because treatment kills the worms but not their eggs, medication should be paired with careful handwashing, morning bathing and regular laundering to help prevent the infection from spreading or returning.
Not sure whether the symptoms are pinworms? Contact a healthcare professional for help with diagnosis. Several other conditions can cause itching or irritation around the anus.
In this guide
- What pinworms are
- Common pinworm symptoms
- How pinworms spread
- How the tape test works
- OTC pinworm treatment
- How to help prevent reinfection
- Frequently asked questions
What are pinworms?
Pinworms, scientifically known as Enterobius vermicularis, are small, thin white roundworms that live in the colon and rectum. Pinworm infection may also be called enterobiasis.
While an infected person sleeps, female pinworms move to the skin around the anus to deposit their eggs. This nighttime activity can cause itching and discomfort. Repeated scratching may make the skin red or swollen and can sometimes lead to a bacterial skin infection.
Pinworms can affect anyone, but infections are especially common among:
- Preschool-aged and school-aged children
- Parents and other household members
- Childcare workers and other caregivers
- People living or working in close-contact settings
Common symptoms of pinworm infection
Some people with pinworms have no noticeable symptoms. When symptoms occur, they may include:
- Persistent itching around the anus, particularly at night
- Redness or irritation from scratching
- Difficulty sleeping or restless sleep
- Irritability related to disrupted sleep
- Occasional abdominal discomfort
- Vaginal irritation if pinworms move to the vaginal area
Small, white thread-like worms may sometimes be visible around the anus two to three hours after the person falls asleep. They may also appear on pajamas or bedding.
How do pinworms spread?
Pinworm infection occurs when someone accidentally swallows microscopic pinworm eggs. This can happen after scratching the affected area and transferring eggs from the fingers or fingernails to the mouth.
Eggs can also spread to:
- Clothing and underwear
- Bedding and towels
- Bathroom surfaces
- Toys and household objects
- Food handled with unwashed hands
According to the CDC, pinworm eggs may survive on objects for two to three weeks if the items are not properly cleaned. This makes careful hygiene important during and after treatment.
How does the pinworm tape test work?
A healthcare professional may recommend a tape test to collect possible pinworm eggs from the skin around the anus. The eggs are microscopic, so collecting them at home does not confirm an infection by itself. The sample must be examined under a microscope.
- Perform the test first thing in the morning before bathing, using the toilet or getting dressed.
- Press the sticky side of clear tape against the skin near the anus.
- Place the tape in a sealed container, zippered bag or specimen container according to your healthcare provider's instructions.
- Repeat the process for three mornings in a row.
- Bring the collected samples to the healthcare professional or laboratory for examination.
Avoid touching your face while collecting the sample and wash your hands thoroughly afterward. Speak with a healthcare professional before performing the test so you know which tape and storage method to use.
How is pinworm infection treated?
Pinworm infection can be treated with over-the-counter pyrantel pamoate or with prescription medicines. Pyrantel pamoate is an anthelmintic medicine that works by paralyzing pinworms so they can pass from the body through the stool.
The amount of pyrantel pamoate needed is based on body weight. Always use the dosing chart on the Drug Facts label instead of estimating the dose by age.
Should everyone in the household be treated?
The CDC recommends treating the person diagnosed with pinworms, their caregivers and household members at the same time to help prevent repeat infections. The PIN RID Drug Facts also direct users to treat the entire household, using the appropriate weight-based dose for each person.
Before treating household members, review the label warnings and ask a healthcare professional about anyone who:
- Is under 2 years old or weighs less than 25 pounds
- Is pregnant or breastfeeding
- Has liver disease
- Has experienced an allergic reaction to pyrantel pamoate or another ingredient
Why do some sources mention a second dose?
The CDC notes that a second treatment dose may be used two weeks after the first because pinworm medicines kill worms but do not kill eggs. However, the PIN RID Drug Facts direct users to take only one dose and not repeat treatment unless directed by a doctor.
Follow the directions for the specific medicine you are using. Ask a healthcare professional whether another dose is appropriate. If signs of pinworms persist after treatment, consult a doctor.
PIN RID Pinworm Treatment Chewable Tablets
PIN RID Pinworm Treatment is an over-the-counter chewable medicine for treating pinworm infection.
- Active ingredient: pyrantel pamoate 720.5 mg, equivalent to 250 mg pyrantel base per tablet
- Format: bubble gum-flavored chewable tablets
- Package: 24 chewable tablets
- Dosing: weight-based according to the Drug Facts chart
- Convenience: no liquid measuring, spills or individual blister packs to open
View PIN RID 24 Chewable Tablets
Prefer another package size or format? Compare all pinworm treatment options, including chewable tablets and oral liquid.
How to help prevent pinworm reinfection
Medication alone cannot remove pinworm eggs from the household. Everyone in the home should follow careful hygiene practices during treatment and for two weeks after the final treatment dose recommended by a healthcare professional.
Prioritize handwashing
- Wash hands thoroughly with soap and warm water.
- Always wash after using the toilet or changing diapers.
- Wash before preparing, serving or eating food.
- Clean beneath the fingernails.
- Discourage nail-biting and scratching around the anus.
Bathe and change clothes every morning
- Shower in the morning to remove eggs deposited overnight.
- Use a shower instead of a shared tub bath when possible.
- Change underwear and sleepwear every morning.
- Do not share or reuse washcloths.
Wash bedding and clothing carefully
- Wash underwear, pajamas, towels, washcloths and bedding frequently.
- Avoid shaking potentially contaminated laundry because eggs can become airborne.
- Wash items in hot water at a minimum of 130°F when the fabric allows.
- Dry items in a hot dryer.
Routine cleaning and vacuuming can also help remove eggs from frequently touched surfaces. The previous recommendation to use UV light or simply open windows has been removed because it is not part of current CDC household prevention guidance.
Frequently asked questions
Are pinworms only found in children?
No. Pinworms are especially common among preschool-aged and school-aged children, but adults can also become infected. Parents, caregivers and household members are at increased risk because pinworms spread easily through close contact.
Can you see pinworm eggs?
Pinworm eggs are microscopic and cannot normally be seen without a microscope. A healthcare professional may ask you to collect a tape-test sample that can be examined for eggs.
Can pets spread pinworms?
No. The type of pinworm that infects humans is not spread by household pets. People cannot give human pinworms to dogs or cats, and pets do not transmit them to people.
Can I use PIN RID for other types of worms?
PIN RID is used for the treatment of pinworm infection. Do not use it for roundworm, hookworm, whipworm or another condition unless a healthcare professional specifically directs you to do so.
Can PIN RID be used for children?
The Drug Facts provide weight-based dosing beginning at 25 pounds. Consult a doctor before use for a child under 2 years old or weighing less than 25 pounds.
What should I do if symptoms continue?
If signs of pinworms persist after treatment, consult a doctor. Continued itching may mean that another treatment decision is needed or that a different condition is causing the symptoms.
Key takeaways
- Nighttime anal itching is the most common pinworm symptom, but some infected people have no symptoms.
- A tape-test sample can be collected at home, but a healthcare professional or laboratory examines it for microscopic eggs.
- OTC pyrantel pamoate is dosed by body weight and should be used according to the specific Drug Facts label.
- Treating caregivers and household members at the same time may help prevent repeat infections.
- Handwashing, morning showers and hot laundering are important because treatment does not kill pinworm eggs.
Not sure which treatment format fits your household? Compare PIN RID pinworm treatment options.
Medical disclaimer: This content is for general educational purposes and is not medical advice. Always read and follow the complete Drug Facts label. Ask a doctor or pharmacist if you have questions about diagnosis, dosing, repeat treatment or whether a product is appropriate for someone in your household.
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