User:Editor-aay/Pinworm infection

Diagnosis
Diagnosis relies on finding the eggs or the adult pinworms. Individual eggs are invisible to the naked eye, but they can be seen using a low-power microscope. On the other hand, the light-yellowish thread-like adult pinworms are clearly visually detectable, usually during the night when they move near the anus, or on toilet paper. Shining a flashlight on the infected individual's anus about one hour after they fall asleep is one form of detection and may show worms crawling out of the anus. Another form of detection is the use of transparent adhesive tape (e.g. Scotch Tape) applied on the anal area which will pick up deposited eggs, and diagnosis can be made by examining the tape with a microscope. This test is most successful if done every morning for several days, because the females do not lay eggs every day, and the number of eggs varies. A third method of diagnosis is examining a sample from under their fingernails under a microscope as itching around the anal area is common and therefore they may have collected some eggs under their nails as a result.

Pinworms do not lay eggs in the feces, but sometimes eggs are deposited in the intestine. As such, routine examination of fecal material gives a positive diagnosis in only 5 to 15% of infected subjects, and is therefore of little practical diagnostic use. In a heavy infection, female pinworms may adhere to stools that pass out through the anus, and they may thus be detected on the surface on the stool. Adult pinworms are occasionally seen during colonoscopy. On a microscopic level, pinworms have an identifying feature of alae (i.e., protruding ridges) running the length of the worm.

Signs and symptoms
One-third of individuals with pinworm infection are totally asymptomatic. The main symptoms are itching in and around the anus and perineum. The itching occurs mainly during the night, and is caused by the female pinworms migrating to lay eggs around the anus. Both the migrating females and the clumps of eggs are irritating, as well as the sticky substance that is produced by the worms when the eggs are laid.

Epidemiology
Pinworm infection occurs worldwide, and is the most common helminth (i.e., parasitic worm) infection in the United States and Western Europe. In the United States, a study by the Center of Disease Control reported an overall incidence rate of 11.4% among people of all ages. Pinworms are particularly common in children with approximately 30% of children being infected and most commonly seen in children between 7 and 11 years old. The prevalence rates in children having been reported as high as 61% in India, 50% in England, 39% in Thailand, 37% in Sweden, and 29% in Denmark. Finger sucking has been shown to increase both incidence and relapse rates, and nail biting has been similarly associated. Because it spreads from host to host through contamination, enterobiasis is common among people living in close contact, and tends to occur in all people within a household. The prevalence of pinworms is not associated with gender, nor with any particular social class, race, or culture. Pinworms are an exception to the tenet that intestinal parasites are uncommon in affluent communities.

Prevention
Pinworm infection cannot be totally prevented under most circumstances. This is due to the prevalence of the parasite and the ease of transmission through soiled night clothes, airborne eggs, contaminated furniture, toys and other objects. Infection may occur in the highest strata of society, where hygiene and nutritional status are typically high. The stigma associated with pinworm infection is hence considered a possible over-emphasis. Counselling is sometimes needed for upset parents who have discovered their children are infected, as they may not realize how prevalent the infection is.

Preventive action revolves around personal hygiene and the cleanliness of the living quarters. The rate of reinfection can be reduced through hygienic measures, and this is recommended especially in recurring cases.

The main measures are keeping fingernails short, and washing and scrubbing hands and fingers carefully, especially after defecation and before meals. Showering every morning is also highly recommended to wash off any eggs that may be still laying on the skin. Under ideal conditions, bed covers, sleeping garments, and hand towels should be changed daily and clothes and linens should be washed in hot water and then be placed in a hot dryer in order to kill off any eggs. Children can wear gloves while asleep, and the bedroom floor should be kept clean. Regular disinfection of kitchen and bathroom surfaces will help to prevent spread as well. Food should be covered to limit contamination with dust-borne parasite eggs. It is not recommended to shake clothes and bed linen as the eggs may detach and spread or to share clothes and towels. Nail biting and sucking on fingers is also discouraged.

Treatment
Medication is the primary treatment for pinworm infection. However, reinfection is frequent regardless of the medication used. Total elimination of the parasite in a household may require repeated doses of medication for up to a year or more. Because the drugs kill the adult pinworms, but not the eggs, the first retreatment is recommended in two weeks. Also, if one household member spreads the eggs to another, it will be a matter of two or three weeks before those eggs become adult worms and thus amenable to treatment. Asymptomatic infections, often in small children, can serve as reservoirs of infection, and therefore the entire household should be treated regardless of whether or not symptoms are present.

The benzimidazole compounds albendazole (brand names e.g., Albenza, Eskazole, Zentel and Andazol) and mebendazole(brand names e.g., Ovex, Vermox, Antiox and Pripsen) are the most effective. They work by inhibiting the microtubule function in the pinworm adults, causing glycogen depletion, thereby effectively starving the parasite. A single 100 milligram dose of mebendazole with one repetition after two weeks, is considered the safest, and is usually effective with cure rate of 96%. Mebendazole has no serious side effects, although abdominal pain and diarrhea have been reported. Pyrantel pamoate (also called pyrantel embonate, brand names e.g., Reese's Pinworm Medicine, Pin-X, Combantrin, Anthel, Helmintox, and Helmex) kills adult pinworms through neuromuscular blockade, and is considered as effective as the benzimidazole compounds and is used as a second-line medication. Pyrantel pamoate is available over the counter and does not require a prescription. Pinworms located in the genitourinary system (in this case, female genital area) may require other drug treatments.

Treatment in Pregnancy and Breastfeeding
The available data on mebendazole, albendazole, and pyrantel pamoate use in pregnancy is limited and they are all assigned to pregnancy category level C. Treatment of a pinworm infection during pregnancy is only recommended for patients with significant symptoms that may be causing adverse effects to the pregnant person such as loss of sleep and weight loss. Pyrantel pamoate is the treatment of choice in pregnancy but should be used only after consultation with a health care practitioner rather than self-treatment. Treatment should be avoided in the first trimester, and if possible done in the third trimester. If the pregnant individual is asymptomatic, then they should be treated after the baby is delivered.

Mebendazole has less than 10% of the oral dose absorbed into systemic circulation with a clinically insignificant amount of drug excreted in breastmilk, and therefore treatment should not be withheld during breastfeeding. There is limited data on the use of pyrantel pamoate and albendazole in breastfeeding but WHO also classifies them as compatible with breastfeeding. This is due to the drugs acting mainly in the intestinal system of the mother with only a very small amount of drug being absorbed into the systemic circulation.