Medical Edge Newspaper Column

Pinworms Treatment As Easy As Acquisition

Nov. 5, 2006
DEAR MAYO CLINIC:
How does a child contract pinworms? What are the symptoms and treatment options? -- Rochester, Minn.

ANSWER:
Pinworms! Just the thought of them can provoke discomfort and anxiety.

But many people who carry pinworms have no symptoms and rarely suffer any ill effects. Even when a pinworm infection does cause symptoms -- anal or vaginal itching, for example -- it's not a dangerous condition. Other symptoms may include irritability, restlessness, insomnia and mild gastrointestinal distress such as intermittent abdominal pain.

Pinworm infections start when microscopically sized eggs reach a person's mouth -- by way of contaminated drink, food or hands -- and he or she unknowingly swallows them.

Inside the body, the eggs hatch and then mature in the intestines, growing up to about half an inch in length. They may then migrate down the length of the intestines to deposit new eggs on the skin surrounding the anus. The egg-laying may result in an itchy bottom, which can lead to scratching. Eggs then get stuck on the fingers and, later, on surfaces that the fingers touch.

The best way to reduce the risk of spreading an infection is to avoid scratching the anal area, washing your hands thoroughly (especially after a bowel movement), and keeping your fingernails clean. The tendency to lapse in performing these practices explains why pinworm infection is much more common in young children than in adults.

It is also important to change linens, nightclothes and undergarments of affected individuals frequently, as often as daily. Otherwise, the eggs can live for two to three weeks, making them more likely to infect someone else. Pets, by the way, do not carry or transmit the infection.

Mild pinworm infections, or those with no symptoms, may never need treatment, as the body eventually rids itself of these parasites. For symptomatic infections, medication is almost always effective in eliminating the pinworms quickly. Mebendazole (Vermox) may be given as a single 100-mg dose, which is then repeated two weeks later. The same dose is given regardless of age or size of the patient, but use in children under two years of age has not been well studied. Pyrantel pamoate (Antiminth, Pin-Rid) and albendazole (Albenza) are alternative treatment options. Because family members are often also infected, some experts suggest treating the whole family.

If itching is severe or interferes with sleep, your doctor may prescribe a soothing ointment or cream to use until the pinworms are eliminated.

-- Philip R. Fischer, M.D., Pediatrics, Mayo Clinic, Rochester, Minn.