Harmless but horrible: how to get rid of pinworms in children

Are you familiar with the intruders who might be living in your intestines? These tiny, white threadlike pinworms, only 3 to 13 mm in size, like making themselves comfortable in your rectum. The pinworm, medically known as Enterobius vermicularis, is very common. Although they’re generally considered a problem in children, they’re one of the most common parasite infections in the USA, where an estimated 12 per cent of the entire population are infected with pinworms. In Western Europe, it’s estimated that 20 per cent of kindergarten and primary school children are affected (link in German). But there are no exact figures.

Similar to head lice, the gross factor is pretty high for pinworms. All the more because the parasite has a different approach to spreading than others of its kind. It doesn’t spread via faeces. Instead – and this is the truly repulsive bit – the female worms usually wait until it’s dark to crawl out of your intestine and lay around 10,000 eggs in your anus (perianal region). «The sticky, gelatinous substance in which the ova are deposited and the movements of the female worm cause perianal pruritus. The ova can survive on fomites (surfaces) as long as 3 weeks at normal room temperature,» reads part of the definition of a pinworm infection (enterobiasis) in the MSD Manuals.

How pinworms are transmitted

In most cases, the eggs are no longer infectious after several days. However, as most carriers are small children and schoolchildren, they keep the worm cycle going. When scratching the itchy anal region, the worm eggs get onto their hands and back into the body through hand-mouth contact. So they ultimately end up in the intestine again. Next, the larvae hatch in the intestine, grow to sexual maturity, crawl out of the anus again and keep the vicious circle going. The problem’s not just ongoing reinfection. The eggs of the worm can also reach other hosts via shared toys, contaminated food (such as salad or fruit), door handles or the sandpit in the playground, for example, where they start a new cycle. Pinworm eggs can also be inhaled via contaminated soil and dust.

What are the symptoms of a pinworm infection?

Many people who are affected have no symptoms at all. Others experience itching in the anus, especially in the evening or at night when the female worms are actively laying eggs. The itching, in turn, can lead to restless sleep. Other symptoms include abdominal pain, diarrhoea and nausea. In girls, the worm may also migrate into the vagina and cause infections. Pain, redness and itching in the vulva and vagina, especially at night, can be a sign of pinworms. In rare cases and only if an infection is severe, inflammation of the intestinal wall (article in German) may also occur in both sexes.

Worm eggs on the anus or the hands aren’t visible to the naked eye. However, you may occasionally be able to spot the white wriggling worms in your faeces. This is a relatively straightforward way to detect enterobiasis. A much more common method with clearer results involves using cellophane. In the morning, a strip of tape is stuck to the anus of the affected person, pressed on and carefully pulled off again. The samples obtained are then placed on a glass slide, so the paediatrician can identify the worm eggs under the microscope and start treatment.

Why do children get infected so often?

According to the German medical publication «Deutsches Ärzteblatt» (article in German), several studies on pinworm infection have identified high-risk factors in children between the ages of four and eleven: «Close social contact, putting toys or writing utensils in the mouth and, in particular, fingernail biting (...) contributes significantly to exposure to Enterobius vermicularis during this phase of life. Scratching the anal area, uncontrolled anus-finger-mouth contact, independent unsupervised personal hygiene and low compliance with hand washing before eating are associated with significantly higher infection rates.»

As the pinworm eggs are so sticky, they adhere particularly well to the hands and under the fingernails, which keeps the infection cycle going. Adults are affected by this, too. If a child is infected, there’s a high probability that the rest of the family will soon be hosting those uninvited tenants in their intestines.

Unless action is taken.

Pinworm infection: which treatment’s effective?

If a pinworm infestation is confirmed, the paediatrician will prescribe a remedy that’s usually taken by all family members. The active ingredients mebendazole, pyrantelembonate and pyrvinium embonate have been approved antihelminthics (link in German) since the 1950s. Only mebendazole acts on both the worm eggs and the adult worms and only needs to be taken once. The other antihelminthics are taken twice with a two-week interval. Although the medication’s considered to be well tolerated, there are occasional side effects including gastrointestinal complaints and headaches.The drugs are not approved for pregnant women.

The good news is that treatment success rates for enterobiasis are high at more than 90 per cent. What’s more of a challenge is to avoid reinfection or autoinfection, writes «Deutsches Ärzteblatt» (link in German).

And this is why, in addition to medication, preventative measures are always part of the treatment for pinworm infestation. Fingernails should be cut short and brushed regularly, especially in children who still often put their fingers in their mouths. What also helps break the worm cycle is to wash your hands carefully after using the toilet and before every meal. Don’t share towels and flannels, change pyjamas and underwear regularly, avoid scratching your anus and clean your private parts daily.

The internet is full of tips on home remedies that can allegedly get rid of pinworms. Garlic, raw carrots, onions, sauerkraut, blueberries, camomile tea, grapefruit seed extract ... If you feel like trying them out, go ahead. However, there’s no scientific evidence that eating these foods alone will get rid of worms. Regarding this matter, the «Ärzteblatt» writes succinctly: «Intestinal lavages, «garlic cures», Carlsbad salt or appendectomies (in the absence of appendicitis) are obsolete.» You’re better off following basic hygiene rules and taking the mentioned medication, which will (hopefully) break the cycle.

The advantages of sharing your gut with worms

If you’re still thinking «yuck», let me tell you: worms and humans have always formed a community and have lived together for thousands of years – and not just pinworms. Various worm parasites are capable of boosting the human immune system, which means both the host and the parasite benefit from an infection, as this study revealed. Today, many scientists believe that the increasing number of allergies and autoimmune diseases including asthma or neurodermatitis is not only due to increasingly hygienic living conditions. But also because most worm diseases have been eradicated in northern and central Europe.

Unfortunately, the pinworm doesn’t have these qualities. It’s not a sparring partner for your immune system, as it only stays in the intestine and – unlike other types of worms – doesn’t migrate through the tissue. Fortunately, it doesn’t harm your health either. It’s just bothersome.