On the surface, a pinworm (Enterobius vermicularis) can seem rather scary. After all, this nematode is the most common parasite in North America, loves to lay eggs on the anus, are found most often in children, and can spread with remarkable speed among families. Fortunately, pinworm infectionsâwhile they can be unpleasant or embarrassingâare not actually dangerous. Equally fortunate is the fact that pinworm treatments exist and are fairly successful at clearing up infections, while certain common-sense behavioral changes will help remove any lingering eggs and prevent the spread of the worms.
Pinworm Infection Causes
A pinworm infection, formally known as enterobiasis or oxyuriasis, begins when you ingest or inhale the creature’s microscopic eggs. This is hopefully unintentional and can come about simply by touching a surface that eggs are lying on, and then touching your mouth.
Once inside the body, pinworm eggs will linger inside the intestines until they hatch and mature into adults. Grown female pinworms will make their way through the colon and out through the anus. They will then proceed to lay eggs in the folds of the anal skin. It is the presence of these eggs that causes the main symptoms of infection.
Symptoms of a Pinworm Infection
Pinworms do not always cause symptoms, both when in the intestine and when laying eggs. When they do cause symptoms, the most common ones are severe itching around the anal or vaginal area. This itching will be more pronounced at night since that is when the worms are most active. Other potential symptoms include insomnia, irritability, and restlessness. The eggs can also sometimes trigger a mild inflammation response, resulting in pain or a rash around the anus.
Perhaps the most disquieting symptom of a pinworm infestation is the appearance of the worms themselves. Pinworms can appear in stool and, if inspected first thing in the morning, they can sometimes be seen around the anus directly. A grown pinworm is around a quarter-inch to half an inch long, so they would be visible to the naked eye.
If left untreated for a prolonged period, pinworms can sometimes migrate to the vaginal area in women and cause urinary tract infections, vaginitis, uterine inflammation, and similar problems. Pinworms are also parasites and will steal nutrients from the body. This can result in unintended weight loss if the infection is able to persist. If pinworms are able to multiply to large enough numbers, abdominal pain and nausea may also appear.
Incidentally, if you suspect someone of having a pinworm infection, it is important that they do not scratch their anal area and, if they do, to wash their hands immediately after doing so. Scratching causes eggs to get picked up under the fingernails and from there the eggs can be deposited onto any surface the person touches. Pinworm eggs can survive for several hours under the fingernails and up to three weeks on an external surface, making it easy for cases to spread.
Risk Factors for Pinworm Infection
Small children are more likely to put objects in their mouth or use their hands for eating. This makes them naturally more susceptible to contracting pinworms. However, adults can get pinworm infections as well. Being in situations that encourage close proximity, such as living in an institutional environment or simply being a family under the same roof, can also raise the risk of contracting pinworms. Infections are known to spread quickly and be potentially undetected among family members.
Sharing clothes and washcloths or towels can also help spread infection, as can interacting with contaminated bed sheets. As mentioned, pinworm eggs can be inhaled, such as when they are sent airborne while shaking out contaminated sheets, clothes, pillow cases.
Pinworm Diagnosis and Treatment
Pinworms are diagnosed using the “tape test”, which is exactly what it sounds like. A piece of cellophane tape is placed on the anus in the morning. The tape will capture eggs if they are present and possibly some lingering worms as well, both of which can be seen by a doctor. For an accurate result, since pinworms don’t lay eggs every night, the CDC advises performing the tape test three times over three consecutive mornings. Since using the bathroom, showering, and other “waking up” activities can displace eggs, it is important to perform the tape test first thing in the morning.
Once diagnosed, pinworms can be treated using anti-parasitic medication, of which there are prescription or over-the-counter options available. You should check with your doctor before using such medication in order to make sure it would be best for your particular situation and other medical conditions (if any).
The typical treatment protocol is to take two doses of the medication, with the second dose coming two weeks after the first. It is important that everyone in the person’s householdâfamily members, caretakers, etc.âundergo treatment at the same time. Pinworms spread easily and reinfection is a very real possibility that needs to be avoided.
The following are examples of steps that should be taken during the treatment and for an additional two weeks following the final dose of medication in order to restrict the spread of the pinworms:
- Proper hand hygiene is the best method of prevention. Wash hands with soap and warm water after using the toilet, changing diapers, before preparing food or eating, etc.
- Keep fingernails short and clean and discourage biting fingernails
- Don’t scratch your butt
- Wash each morning
- Ideally, shower instead of bathe since eggs can persist in the bath water
- Change underclothes, night clothes, and towels frequently
- Use careful handling (i.e.: no shaking) and frequently launder sheets, clothes, etc. in hot water
- Pinworm eggs are sensitive to sunlight, so keep rooms well-lit if possible
- Don’t allow children to bathe together
- Thoroughly wash any surface or object that may be contaminated