Pinworm infections are easily spread from person to person. They are most common in children between the ages of 5 and 10, people who live in institutions, and those who have regular, close contact with individuals in these groups. Pinworms infections are highly contagious; acquiring the infection occurs by unintentional ingestion of pinworm eggs, which have been deposited onto a surface by an infected person. The cycle of infection begins with the ingestion of these microscopic eggs.
Once the eggs have access to the body, they remain in the intestine until they hatch and mature. As adults, the female pinworms travel down the intestine, into the colon, and exit the body through the anus, where they lay eggs in the folds of skin around the anus. The presence of these eggs often causes itching and irritation.
Upon scratching the affected area, the pinworm eggs are transferred to the fingers. The eggs can survive for several hours on hands, such that if the infected person touches bedding, clothing, toilet seats, or any object, the eggs are transferred to these surfaces. Pinworm eggs can survive on these contaminated surfaces for up to three weeks.
One third of individuals with pinworm infection are totally asymptomatic. The main symptoms are pruritus ani and perineal pruritus (itching in and around the anus and around the perineum). The itching occurs mainly during the night and especially around dawn, the time during which the female pinworms migrates to lay eggs around the anus. General symptoms are insomnia (i.e., persistent difficulties to sleep) and restlessness. Pinworms in women may go onto the vulva and into the vagina, from there moving to external orifice of the uterus, and onwards to the uterine cavity, fallopian tubes, ovaries, and peritoneal cavity. This may lead to vulvovaginitis, i.e. an inflammation of the vulva and vagina. As a result, vaginal discharge and pruritus vulvae, i.e., itchiness of the vulva, are reported. The pinworms can also enter the urethra, and presumably, they carry intestinal bacteria with them.
To make the diagnosis of pinworm infection, a tape test is the most reliable method. A piece of adhesive tape is pressed against the skin around the anus. Since pinworms often exit the anus while the infected person sleeps, the tape test gives a better yield when done upon waking in the morning. If eggs are present, they will stick to the tape. The is then examined under a microscope to see if it contains pinworm eggs.
The most common and effective medications to treat pinworm infection are:
• pyrantel pamoate
In addition to medication, hygienic and household cleaning measures can help you completely eliminate the pinworm eggs:
• The infected person and other household members must thoroughly wash their hands with warm water and soap, especially before eating.
• Everyone in the household should shower and change their underwear every morning.
• Fingernails should be well cleaned and cut short.
• The infected person should refrain from scratching the anal area.
• Use hot water to launder all bedding, towels, washcloths, and clothing in the affected house. Dry these items using high heat.
• Avoid shaking clothing and bedding to keep pinworm eggs from spreading into the air.
• Do not allow children to bathe together to prevent spreading pinworm eggs in the bath water.
• Thoroughly clean any surfaces that may be infected, including toys, floors, countertops, and toilet seats.
• Carefully vacuum all carpeted areas.