Q: Every time I take my 2-year-old's diaper off, she begins scratching around her anus. I've heard this might be a sign of "worms." What shall I do?
A: Anal "pruritus," or itching, in a young child may be a sign she has pinworms living in her lower intestine. These slender worms are less than an inch long and appear grayish white. You may or may not see them on your daughter's bottom or in her stool. They crawl out of the rectum to lay eggs around the anus, which is what causes the itching.
Pinworm infestation is a common childhood occurrence and does not cause serious problems. On rare occasions, pinworms may enter the vagina and cause mild irritation there.
Children with pinworms touch their bottoms and then touch toys or other objects, leaving eggs from their fingers. The eggs stick to the fingers of other children who then put their fingers in their mouths and ingest the eggs. The eggs hatch in the small intestine, the worms travel to the lower intestine and lay eggs around the anus, setting up the cycle again.
Take her to the doctor. The tiny pinworm eggs may be visible on sticky tape applied to the skin around her anus then placed on a microscope slide. A simple prescription medicine taken by mouth will rid your daughter of her worms.
Your doctor may choose to treat other young children in the family and any other household members who have symptoms.
Dr. Wilson is director of general pediatrics at the Johns Hopkins Children's Center; Dr. Joffe is director of adolescent medicine.