Enterobiasis overview

Template:Pinworm Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Please help WikiDoc by adding more content here. It's easy! Click here to learn about editing.

Overview

The pinworm (Genus Enterobius) is a parasitic roundworm of the phylum Nematoda. Enterobiasis is the medical condition of being infected with pinworms (Enterobius vermicularis). It may be referred to, less precisely, as oxyuriasis, in reference to the family Oxyuridae, which contains the genus Enterobiasis.

Causes

The human pinworm Enterobius vermicularis and the more recently discovered Enterobius gregorii causes enterobiasis.

Epidemiology and Demographics

The pinworm has a worldwide distribution, 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 prevalence rates in this age group 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, pinworms are 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. The earliest known instance of pinworms is evidenced by pinworm eggs found in coprolite, carbon dated to 7837 BC at western Utah.

Risk Factors

Children are at increased risk of having pinworm infection.

Diagnosis

History and Symptoms

The symptoms may include painful itching around the anus, restless sleep, poor appetite, and failure to gain weight.

Laboratory Findings

Diagnosis is often made clinically by observing the female worm (or many worms) in the peri-anal region, but can also be made using the "scotch-tape" test, in which the sticky side of a strip of cellophane tape is pressed against the peri-anal skin, then examined under a microscope for pinworm eggs.

Medical Therapy

The condition can be treated with mebendazole (Vermox), albendazole, piperazine (Antepar), or mostly commonly pyrantel pamoate (Combatrin, Povan). Also great care should be taken to shower daily, and wash hands before every meal to avoid re-infection. All infected materials (pajamas, bedclothes, and underwear) should be washed with soap and hot water daily. Taking a second dose of medication two weeks after the first will usually kill any pinworms that might have hatched in the meantime, before they are able to produce new eggs. More than one household member is likely to be infected, so the entire household is often treated.