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Intestinal worm infection

Intestinal worm infection

Intestinal worm infection

     Symptoms and causes

    Diagnosis and treatment

General description

Pinworm infection is the most common type of intestinal parasite infection in the United States and one of the most common worldwide. Pinworms are thin and white and are about 1/4 to 1/2 inch (about 6 to 13 millimeters) long.

While the infected person sleeps, the female parasites lay thousands of eggs in the folds of the skin around the anus. Most people infected with pinworm have no symptoms, but some have an itchy anus and restless sleep.

Pinworm infection occurs most often in school-age children, and the tiny (microscopic) eggs are quickly passed from one child to another. Treatment consists of taking oral medications that kill pinworms and thorough washing of pajamas, bedding, and underwear. For best results, the whole family should receive treatment.

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    Bibliography: Mayo Clinic Family Health Book 5th Edition


Symptoms of pinworm infection may include the following:

    Itching of the anal or vaginal area

    Insomnia, irritability, teeth grinding, and agitation

    Stomach pain and occasional nausea

Pinworm parasites often do not cause symptoms.

When to see a doctor

Talk to your doctor if you have severe anal itching, especially at night.

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Accidentally swallowing or breathing in intestinal parasite eggs causes intestinal parasite infection. Tiny (microscopic) eggs can get into the mouth through contaminated food and drink or the fingers. Once swallowed, the eggs hatch in the intestines and mature into adult worms within a few weeks.

Female intestinal parasites pass into the anal area to lay their eggs, which often causes anal itching. When you scratch the itchy area, the eggs stick to your fingers and go under your nails. The eggs are then transferred to other surfaces, such as toys, bedding, or toilet seats. Eggs can also be transferred from contaminated fingers to food, liquids, clothing, or other people.

Intestinal parasite eggs can survive for two to three weeks on surfaces.

Risk factor’s

Risk factors for pinworm infection include the following:

    Be young. A pinworm infection is more likely to occur in children 5 to 10 years of age. Microscopic eggs are easily spread to family members, caregivers, or other children at school or childcare centers. Pinworm infection is rare in children younger than two years old.

    We are living in crowded conditions. Those who live in institutions are at higher risk of getting a pinworm infection.


Typical pinworm infections do not cause serious problems. On rare occasions, heavy infestations can lead to infection of the female genitalia.

The parasite can travel from the anal area to the vagina and the uterus, fallopian tubes, and around the pelvic organs. This can lead to problems such as inflammation of the vagina (vaginitis) and inflammation of the uterus lining (endometritis).

The following are rare complications of pinworm infection:

    Infections of the urinary tract


    Condition of part of the abdomen (peritoneal cavity)


For two weeks, pinworm eggs can stick to certain surfaces, such as toys, faucets, bedding, and toilet seats. So, in addition to regular surface cleaning, methods to help prevent the spread of pinworm eggs and prevent reinfection are:

    Wash in the morning. Because pinworms lay eggs at night, washing the anal area in the morning can help reduce the number of pinworm eggs in the body. Taking a shower can prevent possible recontamination with the tub water.

    Change underwear and bedding daily. This helps remove the eggs.

    Wash clothes in hot water. Wash blankets, pajamas, underwear, washcloths, and towels in hot water to help kill pinworm eggs. Dry your clothes at the maximum temperature.

    Do not scratch yourself. Avoid scratching the anus area. Trim your child’s fingernails, so there is less room for egg accumulation. Suggest that your child not bite his nails.

    Wash your hands. To reduce the risk of contracting or spreading the infection, wash your hands thoroughly After using the bathroom or changing diapers and before eating.

What are pinworms?

The popularly known pinworms are infections by a worm or pinworm called Enterobius vermicularis. This is one of the parasites responsible for most parasitic intestinal infections in our country.

The pinworm can reach ten millimeters in length and is characterized by its delicate and elongated shape and its white color, reminiscent of a worm.

Remember that a parasite is an organism that lives at the expense of another of a different species, feeding on it and being able to cause significant damage or injury without providing any benefit.

Specifically, in this infection, what happens is that, after entering the digestive system through the mouth, the pinworm eggs hatch in the small intestine, and the larvae continue to advance and mature on their way to the large intestine. They transform into adults there, where they embed their heads in the intestinal wall. Females travel from this area to the rectum and anus, usually at night. There they lay their eggs, which adhere to the edges of the anus and the skin around it. The complete cycle of this entire process takes about a month.

An infection that affects 40% of schoolchildren

Although this infection can occur in all ages, it reaches higher rates in children between 5 and 14 years old. In fact, according to the Spanish Pediatric Association, Enterobius vermicularis (pinworm) infection affects 40% -50% of school-age children.

How to recognize pinworm: itching and restless sleep at night

The main symptoms that parents should be aware of to recognize pinworm infection in their children are:

    Itching or itching around the anus.

    Sometimes the infection can spread to the genitals and, in girls, cause vaginal irritation.

    Restless sleep and awakenings of the child during the night.

    Scratching can cause erosions in the skin, which is the entry point for other germs that superinfect it.

    If the intestine is infected with a very high number of worms, abdominal pain may appear – which, at times, can be similar to that of acute appendicitis.

    It should also be taken into account that pinworm infections can be asymptomatic in a large proportion of cases, this being more frequent in adults.

How to definitively diagnose pinworm: visualization of eggs and/or worms

The main methods for the definitive diagnosis of worms are:

    Direct Visualization: Worms (adult worms) can sometimes be seen in the anus region, stool, or underwear. Eggs can also be seen in the perianal area.

    The Graham test: consists of applying an adhesive tape (tape) to the perianal region throughout the night or in the morning before cleaning the area and before defecating. Subsequently, this tape is placed on a slide and examined under a microscope, where the parasite is identified.

    Our doctor will establish the treatment.

    Worm infection is easily cured by taking an antiparasitic drug. Still, before self-medicating, we should always go to the family doctor, who will guide us on the most appropriate treatment for each case.

Likewise, the intensity of the itching and local irritation and persistence may require an assessment by the pediatrician, who will indicate if the child needs any additional treatment.

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