What Happens If Pinworms Go Untreated?

Q: What Happens If Pinworms Go Untreated?

Untreated pinworms are usually mild, but they spread easily and often come back. The rare complications, the risk to your household, and when to get care.

Pinworm is usually a mild infection, and some people have no symptoms at all, but left untreated it tends to keep itching, spread to other people in the home and come back. Less often, it leads to skin infections from scratching or vaginal irritation, and in rare cases to inflammation further inside the body, so it is worth confirming and talking with a clinician rather than ignoring it.

This page explains what can happen when pinworm isn't treated, why it so often returns, which complications are documented, and when to see someone in person. It is general education, not a diagnosis or medical advice.

Are pinworms dangerous?

For most people, no. The CDC calls pinworm the most common worm infection in the United States and describes its symptoms as usually mild. In its overview for clinicians, the CDC says most people with pinworm have no symptoms or signs at all, and that when symptoms do occur, the usual one is itching around the anus.

That does not mean it is harmless to ignore. The itching can be intense, especially at night, and MedlinePlus notes that it can interfere with sleep and make people irritable. And because the eggs spread so easily, one untreated infection rarely stays with one person.

What can happen if pinworms go untreated

The itching and lost sleep continue

Female pinworms leave the intestine at night and lay eggs on the skin around the anus, which is what causes the itching. As long as the infection continues, so can the itching, the disturbed sleep and the restlessness that the CDC and MedlinePlus describe.

You can keep reinfecting yourself

Scratching puts eggs on the fingers and under the fingernails. If those eggs reach the mouth, a new cycle starts. The CDC notes that eggs can survive 2 to 3 weeks on objects such as bedding, clothes and towels if they are not washed or cleaned, so the home itself can keep passing the infection back.

It spreads to the people around you

The CDC says pinworm often infects more than one person in a household, and lists household members and caretakers among the people most often infected. An untreated adult can pass it to a partner, to children or to older relatives, and to people in childcare, schools or care homes. That is why the CDC advises that, when pinworm is treated, the infected person, their household and their caretakers are treated at the same time.

Skin irritation and infection from scratching

The CDC says repeated scratching can make the skin red and puffy and can lead to bacterial skin infections on top of the pinworm infection. MedlinePlus also lists irritated or infected skin around the anus among the symptoms of pinworm.

Vaginal irritation in women and girls

Occasionally, pinworms move from the anus to the vaginal area. The CDC says this can cause irritation and inflammation of the vulva and vagina.

Rare complications

The CDC's clinical overview describes rare inflammatory reactions in the pelvis or in the lining of the abdomen when pinworms reach the female genital tract, and notes that appendicitis has been associated with pinworm in rare cases. MedlinePlus lists loss of appetite and weight as uncommon, and seen in severe infections. These are exceptions, not what most people experience, but they are a reason not to ignore symptoms that go beyond itching.

Do pinworms go away on their own?

MedlinePlus notes that mild infections may not need treatment. The difficulty is that pinworm is very easy to catch again: eggs on the fingers, on bedding and on household surfaces can restart the infection, and the CDC says repeat infections are common, especially among household members. Whether to treat, and who in the home should be included, is a decision to make with a clinician or pharmacist rather than waiting to see.

Good hygiene matters either way. The CDC recommends:

Washing hands with soap and warm water after using the toilet, after changing diapers, and before handling food
Keeping fingernails short and clean, and avoiding scratching and nail biting
Bathing every morning and changing underwear daily to remove eggs laid overnight
Showering rather than taking a tub bath, and not sharing washcloths
Washing night clothes, underwear, towels and bedding in hot water and drying them on a hot setting, without shaking them first

Confirming it is pinworm

Anal itching has many causes besides pinworm, including hemorrhoids, irritation from soaps or wipes, and skin conditions. Before deciding anything, it helps to know whether pinworm is really the cause. The usual test is the tape test, done first thing in the morning, and our guide to the pinworm tape test explains each step. If itching is your main symptom, see itchy anus at night: pinworms or not?

When to see a clinician

You think you or someone in your home has pinworm and you are not sure what to do
The itching keeps coming back, or other people in your home have it too
The skin around the anus looks red, swollen, oozing or very sore
You have vaginal itching, discharge or pelvic pain
You are losing weight without trying, or have symptoms that don't fit pinworm
You are pregnant or breastfeeding

Severe belly pain, fever or vomiting needs prompt in-person care, not an online visit.

Options for adults

Two medicines are labeled for pinworm in the United States: pyrantel pamoate, which is sold over the counter, and mebendazole, which needs a prescription. Our guide to pinworm treatment for adults explains how they differ, how to involve the household, and the hygiene steps that matter. We don't publish doses or schedules on this site. The package label or your prescriber sets those.

If you and a provider decide a prescription is appropriate, Get It Prescribed connects adults with an independent licensed provider online. The service is available in all 50 states and the District of Columbia, and some states require a live phone or video visit. The cost is a one-time $50 provider consultation fee, plus $3.50 per capsule for mebendazole if a prescription is issued, with the quantity decided by the provider. No prescription is guaranteed, and the provider may recommend an in-person visit or testing instead. See how it works for each step.

The mebendazole dispensed through Get It Prescribed is a 222 mg capsule prepared by a licensed compounding pharmacy. It is a compounded preparation. It is not FDA-approved, it has not been reviewed by the FDA for safety, effectiveness or quality, and it is not a generic of or substitute for the brand-name mebendazole chewable tablet.

This article is general education, not medical advice. It does not replace an evaluation by a licensed clinician who knows your history.

Sources

CDC: About Pinworm Infection — symptoms, skin infection from scratching, vaginal irritation, how pinworm spreads and how long eggs survive on objects.
CDC: Clinical Overview of Pinworm Infection — most people have no symptoms, and the rare complications, including appendicitis.
CDC: Preventing Pinworm Infection — hygiene steps and why repeat infections are common.
MedlinePlus: Pinworms — overview of pinworm, sleep and irritability from itching, and that mild infections may not need treatment.
MedlinePlus: Pinworms (Medical Encyclopedia) — symptoms, including infected skin and uncommon loss of appetite and weight.
DailyMed: mebendazole chewable tablet prescribing information — labeled uses, including pinworm.
FDA: Compounding and the FDA — Questions and Answers — what compounded preparations are and how they are regulated.

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