Pinworms are small worms that infect the intestines. They are common in children and easy to treat.

Pinworms are the most common worm infection in the United States, primarily affecting school-age children. Pinworm eggs are spread directly from person to person or by touching bedding, food, or other items contaminated with the eggs.

Typically, children are infected by unknowingly touching pinworm eggs and putting their fingers in their mouths. The eggs are swallowed, and eventually hatch in the small intestine. The worms mature in the colon. Female worms then move to the child's anal area, especially at night, and deposit more eggs. This may cause intense itching and the area may even become infected. When the child scratches the itching anal area, the eggs can get under the child's fingernails and be transferred to other children, family members, and items in the house.

• Intense itching around the anus
• Difficulty sleeping due to the itching that occurs during the night
• Irritability due to itching and interrupted sleep
• Vaginal irritation or discomfort in young girls (if an adult worm enters the vagina rather than the anus)
• Irritated or infected skin around the anus, from constant scratching
• Loss of appetite and weight (uncommon but can occur in severe infections)

Pinworms can be spotted in the anal area, especially at night when the worms lay their eggs there. Your doctor may have you do a tape test. A piece of cellophane tape is pressed against the skin around the anus, and removed. This should be done in the morning before bathing or using the toilet, because bathing and wiping may inadvertently remove any eggs. The doctor will stick the tape to a slide and look for eggs using a microscope.