What Increases Your Risk

Factors that increase the risk of being infected by pinworms include:

• Age. Pinworm infections are most common in preschool and school-age children.¹
• Household contact. If one child in a home gets a pinworm infection, it is likely that other children in the home will have the infection. Parents are also more likely to get the infection.
• Attending day care centers, schools, and summer camps. Pinworms are easily transmitted and spread among groups of children.
• Living in an institution. Up to half of people living in an institution may be infected by pinworms.¹

Factors that increase the risk of spreading pinworm infections include:

• Living in an institution. Pinworms are easily transmitted and spread where people are living in close conditions (such as institutions).
• Poor hygiene practices, especially poor hand-washing. An infected person can spread pinworms to others if he or she does not wash his or her hands well.
• Sharing bedding. Also, fanning the bedding of an infected person can release pinworm eggs into the air.

When To Call a Doctor

Call your doctor if:

• You or your child has symptoms of pinworm infection, and no one in your household has had the infection before.
• You see pinworms on your child (when bathing the anal area or wiping his or her bottom) or on your child's bedding or clothes.
• You or your child has symptoms, you have not seen any worms, and you want to see the doctor even though you or your child has had the infection before.
• You have started over-the-counter medicine to treat the pinworms, and the infection has not cleared up. (Do not use an over-the-counter medicine for pinworms in a child younger than 2 without first talking to a doctor.)
• You have had a pinworm infection recently and now have symptoms of reinfection.
• Your doctor prescribed medicine for pinworms, and the infection has not cleared up within the expected time frame (usually within 4 to 6 weeks).
• You or your child is having side effects from medicine for pinworm infection.
• You or your child with a pinworm infection develops other symptoms.
  • Fever or abdominal pain may be a sign of complications of pinworm infection.
  • Redness, tenderness, or swelling in the genital area may be a sign of skin infection.
  • Itching in the genital area or vagina may be a sign of vaginal pinworm infection.
  • Pain when urinating, frequent or urgent urination, or lack of control of urination may be a sign of pinworm infection of the urinary tract.

Watchful Waiting

Watchful waiting is not appropriate when a person has symptoms of a pinworm infection. Although pinworm infections are usually mild and do not cause any serious health problems, treatment should be considered because it helps stop the spread of the infection to others and helps prevent reinfection.

Watchful waiting may not be appropriate for family members of a person infected with pinworms. If one member of a family has a pinworm infection, it is very likely that other members also are infected. This is very important if a family member is pregnant. A pregnant woman may not be able to take pinworm medicine, and treating all other members of the household may decrease the likelihood of her getting the infection. Some doctors recommend treating all members of the family to help prevent reinfection and the spread of infection.

Who To See

Health professionals who can diagnose and treat pinworm infections include:

• Nurse practitioners (NP).
• Physician assistants (PA).
• Pediatricians.
• Family medicine doctors.
• Internists.

If complications of pinworm infection develop, you may need to see a specialist who deals with conditions affecting the body system involved, such as:

• A gastroenterologist.
• A urologist.
• An infectious disease specialist.
• A gynecologist.

To prepare for your appointment, see the topic Making the Most of Your Appointment.