Pinworms (threadworms): symptoms, causes, and treatments

Pinworms (threadworms): symptoms, causes, and treatments

Sleep disturbance is a common symptom of pinworms (threadworms).

The pinworm, also known as threadworm, is a very common intestinal parasite. Enterobiasis, or oaxyuriasis refers to the medical condition associated with pinworm infestation.

According to the CDC (Centers for Disease Control and Prevention), pinworms are the most common type of worm infection in the United States.

They are parasites, meaning that they use the human body to survive and reproduce. Human pinworms cannot infect any other animals.

Adult worms are just 0.2-0.4 inches (5-10 millimeters) in length - about the size of a staple; they are white or cream colored and look like small pieces of thread. Pinworms can live for up to 6 weeks.

Pinworms do not always cause symptoms, but some patients may experience itchiness and discomfort around their anus and females may experience itchiness in the vaginal area. Here we will explore the causes, symptoms, and treatments in more detail.

  • The worms mature in the intestine and then move through the digestive system to lay eggs, at night, in the anal area.
  • The itchiness tends to be worse or more noticeable at night, and can sometimes wake the patient.
  • A pinworm can lay thousands of microscopic eggs.
  • Pinworm eggs are not visible to the naked eye.

What are the symptoms of pinworms?

If the patient only has a small number of adult worms, the symptoms will be mild or there may be no symptoms at all. Symptoms are worse with heavy or moderate infections.

About 4 weeks after ingesting pinworm eggs, the mature females make their way out from the intestine to the anal area, where eggs are laid in a jelly-like substance.

It is this substance that is believed to cause a person to itch, which usually happens at night. During the maturing and reproduction stages, the patient may experience:

  • disturbed sleep
  • itching of the anal area, may sometimes be intense, especially at night when the female worms are laying eggs
  • mild nausea

Individuals with severe infection may experience:

  • loss of appetite
  • severe irritability
  • intermittent abdominal pain
  • sleeping difficulties
  • weight loss

If somebody is found to have an infection, all other members of the household should be treated too, even if they have no symptoms.

Causes of pinworm infection

The cause of pinworm infection is inadequate hygiene.

Eggs are transferred from the anus of an infected person to either their own mouth (re-infecting themselves) or another surface. If somebody else touches that contaminated surface and then touches their mouth, they may have ingested the eggs and can become infected.

The female pinworm lays eggs around the anus and vagina. The eggs can be transferred from the person's anus to:

  • bed sheets
  • carpets
  • hands
  • towels
  • underwear and clothes

The female pinworm releases an itchy mucus when laying her eggs, triggering an urge to scratch the affected area of the anus or vagina. From the hands, the eggs may be transferred to anything that is touched, including:

  • bathroom utensils - toothbrushes, combs, and brushes for example
  • directly to other people's hands - if the hands of an infected person touch the hands of another
  • furniture
  • kitchen and bathroom surfaces
  • kitchen utensils
  • toys

Swallowing the eggs

The eggs can survive for up to 3 weeks on surfaces. If they are touched, they will be transferred onto the hands. If the hands then touch the person's mouth, there is a serious risk of swallowing the eggs and becoming infected.

Breathing in the eggs

The microscopic eggs may become airborne and then be breathed in and swallowed. This can happen when shaking towels or bed sheets, for example. The eggs hatch in the intestines in 1-2 months after being swallowed. After that, the pinworm is able to lay eggs.

Poor hygiene among children

Small children are more likely to become infected because they tend to be less thorough about hand washing. Children may also have long-lasting infections because they are swallowing fresh eggs continually - children are usually in close contact with each other and share items and hold hands while playing, making re-infection more likely.


Pinworms are more common in crowded conditions.

Pet hygiene

Pinworms that affect humans cannot infect animals or pets. However, some microscopic eggs may land on a pet's fur and then be transferred to human hands when petting or playing with them. It is important to remember that the problem is not the pet; it is down to human hygiene.

How are pinworms diagnosed?

The following methods can be used to diagnose pinworms:

Tape test

This test uses cellophane tape. The doctor places a piece of clear plastic tape against the skin around the patient's anus and then looks at the tape under a microscope. As the worm tends to lay her eggs at night, good samples are more likely early in the morning. Patients may themselves apply the tape before using the bathroom or bathing. The sample should then be taken to the doctor.

Moistened swab

A doctor or nurse may take a moistened swab from around the anal area.

Sighting a worm

Sometimes the worms are visible in the anal area, underwear, or in the toilet. In stools, the worms look like small pieces of white cotton thread. Because of their size and white color, pinworms are difficult to see. The male worm is rarely seen because it remains inside the intestine. It is best to search for pinworms at night, when the female comes out to lay her eggs. If you are checking children, it is best to inspect about 2-3 hours after they have fallen asleep.

When to see a doctor

If you are pregnant, breast-feeding, or have a baby less than 6 months of age, and you suspect you may have pinworms, you should see your doctor straight away.

Treatments for pinworms

Pinworm infection can be easily treated. It is important to remember that treatment also focuses on preventing re-infection. All members of the family need to be treated. Treatment may consist of either a 6-week strict hygiene method, or medication followed by strict hygiene for 2 weeks.

Some medications are available OTC (over the counter) at local pharmacies. It is important to follow the manufacturer's instructions. Individuals who are pregnant, breast-feeding, or have a baby less than 6 months old should speak with a doctor.

Hygiene method

Hygiene and cleaning is an effective method for removing pinworms in a home.

Strict hygiene measures can clear up pinworm infection and significantly reduce the risk of re-infection.

The worm has a life span of about 6 weeks, so hygiene measures need to last at least that long. Everyone in a household with pinworms must adhere to the following:

  • Wash all bed linen, bedclothes, and cuddly toys - normal washing temperature is acceptable, but it needs to be well rinsed.
  • Vacuum the home thoroughly, especially the bedrooms - vacuuming needs to be regular and thorough throughout the 6-week period.
  • Damp-dust surfaces in the kitchen and bathroom, washing the cloth often in hot water - do this regularly throughout the period.
  • Do not shake things that may have eggs on them - such as clothing, pajamas, bed linen, or towels.
  • Do not eat in the bedroom - there is a risk of swallowing eggs that have shaken off the bedclothes.
  • Make sure everybody's fingernails are cut short.
  • Refrain from nail biting and finger sucking - this may not be easy if there are small children in the house.
  • Wash your hands thoroughly and frequently, and scrub under fingernails - before eating, after going to the toilet, and after changing diapers, make sure to wash hands.
  • At night, wear close-fitting underwear - change underwear every morning.
  • Cotton gloves - this may help prevent scratching during sleep.
  • Have a bath or shower regularly - thoroughly cleaning the body, paying particular attention to the anal and vaginal areas. Showering is preferred to avoid contaminating bath water.
  • Do not share towels or face flannels.
  • Toothbrushes should be kept in a closed cupboard and rinsed well before use.

When the infestation has gone, good hand-washing practice and hygiene will help prevent re-infection. Good hygiene can prevent another outbreak even if children pick up another pinworm infection from friends at school.

Medication for pinworms

If medication is used, it should be given to everybody in the household. There is a risk of transmission between family members (people in the same household); so the chances of being infected if somebody has been diagnosed are high, even if no symptoms are present. Currently, the CDC recommends the following treatment for pinworms.

  • Mebendazole - this medication blocks the worm's ability to absorb glucose, effectively killing it within a few days. It can be taken in chewable form or as a liquid. A 100 milligrams dose is taken and usually repeated in 2 weeks.
  • Pyrantel pamoate - this medication is available over the counter for the treatment of pinworms. It paralyzes the worms. The dose is taken and repeated in 2 weeks.
  • Albendazole - like mebendazole, this medication also blocks the worm's ability to absorb glucose. One 400 milligram dose is taken then repeated in 2 weeks.

Hygiene measures should be continued for the 2 weeks following the initial treatment.

Pregnancy and breastfeeding

The hygiene method is usually recommended for pregnant or breast-feeding mothers, rather than medication. Neither mebendazole or albendazole should be taken during the first 13 weeks of pregnancy.

During the 2nd and 3rd trimesters of pregnancy and during breast-feeding, medication can be used if necessary. This decision should be made by a doctor.

Pyrantel should not be taken during pregnancy without approval by a doctor.

Infants and Children

Talk to a doctor for children under 2 who need treatment. The hygiene method is often preferred. If other treatment is necessary, they can recommend the medicine that is appropriate and safe for the child's age.

What are the complications of pinworms?

Though uncomfortable and sometimes alarming, complications as a result of pinworm infection are rare. However, if they do occur, they can include:

  • Urinary tract infection - this is more common in females with a heavy pinworm infestation. The worm may also migrate to the bladder, causing cystitis.
  • Peritoneal cavity infection - in females, the worm may migrate from the anal area into the vagina and to the uterus, fallopian tubes, and around the pelvic organs, causing vaginitis or endometritis.
  • Weight loss - if the infection is severe, the parasite may leech essential nutrients, resulting in weight loss.
  • Skin infection - the itching may lead to intense scratching, which might break the skin, raising the risk of infection.
  • Appendicitis - there are cases of pinworms migrating into the appendix.

Medication will be required for serious infections or complications. Prevention is usually achievable through adequate hygiene measures. There are no serious or immediately life-threatening complications. As long as treatment occurs soon after symptoms appear, pinworms are a parasite that can be easily handled.

Pinworm Treatment -- 5 Signs You may Have Them with Over 10 Ideas to Help Kill Them! (Video Medical And Professional 2020).

Section Issues On Medicine: Disease