Pinworm – Symptoms and Causes
Overview
Pinworms are small, white parasites that commonly infect the intestines. They typically measure about 1/4 to 1/2 inch (6 to 13 millimeters) in length.
These thin, thread-like worms are the most common intestinal parasite in the United States and are found worldwide.
Many people with pinworms show no symptoms at all. However, some experience intense anal itching, especially at night.
This happens because female pinworms move to the anal area during sleep to lay thousands of tiny eggs in the skin folds around the anus.
Children in school settings are particularly vulnerable to pinworm infections.
The microscopic eggs spread easily from child to child through:
- Contaminated hands
- Shared toys
- Bedding
- Bathroom surfaces
For effective treatment, doctors recommend:
- Medication for the entire family
- Thorough washing of pajamas
- Cleaning all bedding
- Washing underwear in hot water
Several effective medications are available to eliminate pinworm infections. These treatments typically require just one or two doses, with a follow-up dose two weeks later to prevent reinfection.
Signs of Pinworm Infection
Pinworm infections may cause itching around the anus or vagina. Some people have trouble sleeping, feel irritable, grind their teeth, or seem restless. Others might have:
- Stomach pain (occasional)
- Nausea
- Discomfort at night
Many people with pinworms show no signs at all. The absence of symptoms doesn’t mean the infection isn’t present.
When to Call a Medical Professional
If you have bad anal itching, especially when trying to sleep, you should contact your doctor. This symptom may need medical attention to find the cause and get proper treatment.
Causes
Pinworm infections happen when a person accidentally swallows or inhales the microscopic eggs. These tiny eggs can reach your mouth through:
- Contaminated food or drinks
- Unwashed fingers
- Touching surfaces with eggs present
After being swallowed, the eggs hatch inside the intestines and grow into adult worms within weeks.
The female worms travel to the anal area to lay eggs, which creates itching. When someone scratches this itchy area, eggs stick to their fingers and get under fingernails.
These eggs can then spread to:
- Toys
- Bedding
- Toilet seats
- Food and drinks
- Clothing
- Other people
The eggs are quite hardy and can survive for two to three weeks on various surfaces. This long survival time helps explain why pinworm infections can spread easily, especially in settings where people live closely together.
Risk Factors
People face different chances of getting pinworm infections based on certain factors:
Age: Children between 5โ10 years old have the highest risk. Pinworms rarely affect children under 2 years old.
Family exposure: Family members of infected people often get pinworms too, as the eggs spread easily through households.
School and daycare: Children in group settings easily pass eggs to each other through shared surfaces and direct contact.
Crowded living conditions: People in institutions or crowded housing face greater risk due to close quarters.
Complications
Most pinworm infections are mild with no serious effects. However, in rare cases, heavy infestations can lead to problems, particularly in females.
The parasites can sometimes travel from the anus to the female reproductive system, reaching the vagina, uterus, fallopian tubes, and surrounding pelvic organs. This migration may cause vaginal inflammation (vaginitis) or inflammation of the uterine lining (endometritis).
Other uncommon complications might include:
- Urinary tract infections
- Weight loss
- Infection in the abdominal cavity
These complications are rare and typically only occur with severe, untreated infections.
Prevention
Pinworm eggs can stick to many household surfaces for up to two weeks. Here are effective ways to prevent their spread:
Daily Hygiene Practices
- Wash the anal area each morning to remove eggs laid overnight
- Shower rather than bathe to avoid recontamination
- Change underwear daily
- Keep fingernails short to prevent egg collection
- Avoid scratching the anal area
Proper Hand Washing
Wash hands thoroughly:
- After using the bathroom
- After changing diapers
- Before eating or preparing food
Laundry Management
| Item | Washing Instructions |
|---|---|
| Bedsheets | Hot water, high heat drying |
| Pajamas | Hot water, high heat drying |
| Underwear | Hot water, high heat drying |
| Towels | Hot water, high heat drying |
Surface Cleaning
Clean frequently-touched surfaces regularly, including:
- Toilet seats
- Bathroom faucets
- Toys
- Door handles
