Enterobiasis or pinworm infection, as it is commonly called, is an intestinalinfection caused by the parasitic roundworm called Enterobius vermicularis. The most common symptom of this irritating, but not particularly dangerous, disease is itching around the anal area.
Enterobiasis is also called seatworm infection or oxyuriasis. It can affect people of any age, but is most common among children ages 5 and under and particularly affects those in the daycare setting.
The disease is highly contagious and is caused by a parasitic worm called Enterobius vermicularis. The adult female worm is about the size of a staple (approximately 1 cm long and 0.5 mm wide) and has a pointed tip. The disease is transmitted by ingesting the eggs of the pinworm. These eggs travel tothe small intestine where, after approximately one month, they hatch and mature into adult worms. During the night, the female adult worms travel to thearea around the anus and deposit eggs in the folds of the anal area. A singlefemale pinworm can lay 10,000 eggs and, after laying eggs, dies. The eggs are capable of causing infection after six hours at body temperature.
Significant itching in the anal region is caused by the movement of the adultworm as the eggs are deposited. When an individual scratches the anal region, the tiny eggs get under the finger nails and in the underwear and night clothes. Anything the individual touches with the contaminated fingers, for example, toys, bedding, blankets, bathroom door knobs, or sinks, becomes contaminated. The eggs are very hardy and can live on surfaces for two to three weeks. Anyone touching these contaminated surfaces can ingest the eggs and becomeinfected.
Many individuals with enterobiasis exhibit no symptoms. When present, however, symptoms of the infection begin approximately two weeks after ingesting thepinworm eggs. The main symptom is itching around the anus. Because the itching intensifies at night, when the female worms comes to the anus to lay eggs,it often leads to disrupted sleep and irritability. Poor sleeping at night in small children can be related to pinworms. Occasionally, the itching causessome bleeding and bruising in the region, and secondary bacterial infectionscan occur. In females, the itching may spread to the vagina and sometimes causes an infection of the vaginal region (vaginitis). Enterobiasis usually lasts one to two months.
First, a physician will rule out other potential causes of the itching, suchas hemorrhoids, lice, or fungal or bacterial infection. Once these have beenruled out, an accurate diagnosis of enterobiasis will require that either theeggs or the adult worms are detected.
In order to collect a specimen of the eggs for laboratory diagnosis, the physician may provide a paddle with a sticky adhesive on one side, or an individual may be instructed to place a piece of shiny cellophane tape sticky side down against the anal opening. The best time to perform this test is at night or as soon as the individual wakes up in the morning, before having a bowel movement or taking a bath or shower. The pinworm eggs will stick to the tape, which can then be placed on a specimen slide. When under a microscope in the laboratory, the eggs will be clearly visible.
In order to treat the disease, either mebendazole (Vermox) or pyrantel pamoate (Pin-X) will be given in two oral doses spaced two weeks apart. These medications eradicate the infection in approximately 90% of cases. Re-infection iscommon and several treatments may be required. Because the infection is easily spread through contact with contaminated clothing or surfaces, it is recommended that all family members receive the therapeutic dose. Sometimes a series of six treatments are given, each spaced two weeks apart.
To relieve the rectal itching, a shallow warm bath with either half a cup oftable salt, or Epsom salts is recommended. Also, application of an ointment containing zinc oxide or regular petroleum jelly can be used to relieve rectalitching.
Pinworms cause little damage and can be easily eradicated with proper treatment. The disease can be prevented by treating all the infected cases and thuseliminating the source of infection. Some ways to keep from catching or spreading the disease include the following recommendations:
- Wash hands thoroughly before handling food and eating.
- Keep finger nails short andclean.
- Avoiding scratching the anal area.
- Take early morningshowers to wash away eggs deposited overnight.
- Once the infection has been identified, and treatment is started, change the bed linen, night clothes, and underwear daily.
- Machine wash linens in hot water and dry with heat to kill any eggs.
- Open the blinds or curtains since eggs aresensitive to sunlight.