Frequently asked questions about pinworm infection
The more you know about pinworm, the better you can spot the symptoms and protect yourself and your family against infection.
Pinworms—also known as seatworms and threadworms—are little, highly contagious parasites. Pinworms are small, thin, white worms that live in the intestine.1
When someone has pinworms, it is also known as a pinworm infection.1
In most cases, pinworm infections are not dangerous. However, intense scratching—a common symptom of pinworm—can cause a skin infection.1,2
In rare cases, pinworms carry bacteria from the anal area to the urinary tract, which may result in recurrent urinary tract infections.3
You cannot take a pill in advance to prevent a pinworm infection. Because the eggs are so small, a child can bring home the eggs unknowingly from school or a friend’s house. Once your family is treated for pinworm, you can take steps to avoid reinfection.
To help prevent reinfection, follow these tips:
- Wash hands thoroughly and frequently with soap and water. This is especially important after using the toilet, changing diapers, and before preparing or eating food.2
- Cut fingernails short and avoid nail biting. Eggs collect under the fingernails. Consider buying a nail brush for each family member, and sanitize the brushes after each use.4
- As much as possible, discourage children from scratching their bottoms, especially near the anal area—that’s where the eggs are. If you see your kids scratching their bottoms, have them wash their hands.4
- Change and wash underwear, pajamas, towels, and bed sheets daily. Pinworm eggs can contaminate clothing and bedding.2
- Do NOT shake out towels or bed sheets. The tiny eggs can become airborne and inhaled or deposited onto food and swallowed, which can spread the infection. Consider wearing a surgical mask when cleaning to avoid breathing in eggs.2,4
- Clean the bedroom floor by vacuuming or damp mopping. Avoid dry sweeping, which may stir up dust.4
- Disinfect doorknobs, toilet seats, furniture, countertops, cell phones, remote controls, and other shared surfaces the infected person may have touched, as eggs can survive up to 3 weeks on indoor surfaces.2
The most common symptom of pinworm infection is intense scratching of the bottom. This is caused by sticky eggs laid by the pinworms around the infected person’s anal area while the person sleeps at night.1,4
People with pinworm infection may also sleep poorly, be irritable, and be restless. The intense scratching of the bottom may also lead to a bacterial infection.1,2,5
Less common signs of pinworm infection include abdominal pain, teeth grinding, weight loss, bed-wetting, pain while urinating, and nausea.1,5,6
Scratching of the bottom will cause pinworm eggs to stick to fingers. Without thoroughly washing one's hands, anything the infected person touches, such as clothing, bedding, towels, toilet seats, cell phones, remote controls, and other shared surfaces, can get pinworm eggs on it that can be spread to others. Not treating an infected person increases the risk of spreading the infection.2,4,7
A pinworm infection can be detected 2 ways:
- Using a flashlight, look for the worms around your child’s anal area 2 to 3 hours after bedtime. Pinworms look like small pieces of white thread on the skin. Keep in mind, pinworms are not easily visible.8
- Using the “tape test,” apply clear tape around the anal area, while wearing gloves, to collect eggs first thing in the morning. Pinworm eggs can only be seen under a microscope, so put the tape in a sealed plastic bag and take it to your doctor. Make sure to wash your hands thoroughly with hot, soapy water after placing the tape in the plastic bag.2
If you are uncomfortable doing these tests, call your doctor to set up an appointment.
If you see your child scratching their bottom, and they are restless at night, you should call your doctor. You do not have to confirm that your child has pinworm before calling your doctor.1,5
Pinworm can be treated with EMVERM (mebendazole). You can only get EMVERM by seeing your doctor, because EMVERM is only available by prescription. EMVERM is 95% effective against pinworm.9
EMVERM comes in a chewable, kid-friendly tablet that can also be swallowed or crushed and mixed with food. Your doctor may prescribe EMVERM for everyone in the household, because others are likely to be infected.2,7,9
The dose for adults and children aged 2 years and older is the same: one 100 mg tablet, taken once. If the patient is not cured 3 weeks after treatment, a second course of treatment is advised.9
Once pinworm eggs are spread around the house, the eggs can live on indoor surfaces for up to 3 weeks.2 However, new infectious pinworm eggs can always be brought back into your household unknowingly.
Because pinworm can come back, doctors may prescribe a second course of treatment. Besides the infected person, your doctor may also want to treat other children in the house or all family members, including adults. The medicine used to treat pinworm infection kills the pinworms but not the eggs. For this reason, your doctor may prescribe 2 courses of treatment about 3 weeks apart to prevent any reinfection.7,9
