Does everyone have pinworms?

SDStaff Lynn Bodoni replies:

Enterobius vermicularis. Alternative names: seatworm; enterobiasis Enterobius vermicularis; oxyuriasis; threadworm; pinworm infection

Mom was right. You should always wash your hands thoroughly with soap after using the bathroom and before handling food or eating. We don’t all have pinworm, but an awful lot of us do.

Pinworm is the most common human worm infection in the United States. According to various reports, rates of infection vary from 10% to almost 50% in children under 12, depending on the group. School-age children have the highest incidence of infection, followed by preschoolers. Like lice, pinworm is readily spread through schools and child care centers. Adults are much less likely to have pinworm, unless the adult is a caretaker of infected children. Sometimes pinworm is spread to other family members as well. Pinworm eggs are collected on the fingers, generally when the patient scratches his itchy bottom. From there, the eggs can be spread to other surfaces, where they can live for several days, just waiting to be picked up and swallowed by their next host. If the patient puts his fingers in his mouth, the eggs can be swallowed and reinfect him. These pinworms, incidentally, infect only humans and a few kinds of apes. They do not infect common household pets.

The most common, and often only, symptom of pinworm infection is anal pruritis (an itchy butt). Pinworms can be seen with the naked eye. The best time to check is at night or early in the morning, before the suspected carrier gets up, and particularly before bathing or bowel movement. Use a flashlight. The worms are about .25 inch long and rather threadlike. They will move. The females come out at night to lay eggs in the rectal area. If the eggs are left to hatch, the immature larvae will crawl back through the anus and wind up back in the colon. Occasionally, in girls, the larvae will crawl into the vagina instead.

If the diagnosis is uncertain, a physician can issue a “pinworm paddle” which is basically a tongue depressor with sticky tape on one end. The paddle is pressed against the anal skin of the patient. If pinworm eggs are present, they will show up on the paddle.

Most sources say pinworms are usually harmless. Some even say that it doesn’t need to be treated, unless the symptoms really bother the patient. However, this is not something I’d want to have. Fortunately, the treatment is very simple, consisting of two doses of medicine two weeks apart. The majority of sources recommend treating all family members at once, even if only one person shows signs of infestation. Most doctors will also recommend washing all the family linen and night clothes in hot water, to remove any eggs that might be floating around.

Only one source that I read advocated garlic as a cure for pinworms, and that source also indicated that pinworms infected dogs and cats, too. Since every other source said pinworm was not spread by household pets, I’m disinclined to give any weight to the theory that garlic can reduce or cure a pinworm infection.

Sources:

http://www.cdc. gov/ncidod/dpd/parasites/pinworm/factsht_pinworm.htm

http://callyourped.com/pinworms.html

http://www.clark.net/pub/electra/cse0608. html

http://familydoctor.org/handouts/139.html

http://www.healthcentral.com/mhc/to p/001152.cfm

http://www.vh.org/Patien ts/IHB/Peds/Infectious/Pinworm.html

http://www.drgreene.com/970402.asp

http://www.emedicine.com/cgi-bin/foxweb.exe/showsection@d:/em/ga?book=emerg &to picid=424

SDStaff Lynn Bodoni, Straight Dope Science Advisory Board

Send questions to Cecil via cecil@straightdope.com.

STAFF REPORTS ARE WRITTEN BY THE STRAIGHT DOPE SCIENCE ADVISORY BOARD, CECIL’S ONLINE AUXILIARY. THOUGH THE SDSAB DOES ITS BEST, THESE COLUMNS ARE EDITED BY ED ZOTTI, NOT CECIL, SO ACCURACYWISE YOU’D BETTER KEEP YOUR FINGERS CROSSED.