What is a Pinworm?
Pinworm , also called Enterobius vermicularis, is a parasite that lives in the human intestinal tract . Its found worldwide .
What do they look like?
The adults are small white and short that have a pointed pin like tail. The female is much larger than the male measuring 8 – 13 mm long and 0.3-0.5mm thick as compared to the male which is 2-5 mm and 0.1 -0.2 mm thick. In The pregnant female worm , literally the whole body is full of thousands of eggs.
The Pinworm lives its whole life cycle in the human host . It has no intermediate host .The adult worms live in the appendix and upper part of the colon . The male worms do not migrate and die soon after mating . The female worm migrates down to the lower part of the colon to the rectum , at night when the host ( infected person) is in bed, the worm comes out through the anus and crawls around the anus and surrounding genital skin and lays its sticky eggs . The worm may return and come back again to lay more eggs , it may also wonder around the vagina and uterus .
A single worm lays about 5000 – 17000 eggs . The egg is colorless and oval but slightly elongated . The outer layer of the egg is sticky making it adhere to clothing and skin .The egg hatches and becomes infectious 6 hrs after being laid on the skin . If conditions are cool and moist the egg can survive for about 2 weeks .
If the eggs are swallowed ( especially after scratching and eating without washing hands or nail biting ) they hatch in the intestine . It takes 2 weeks – 2 months from the the time the eggs are swallowed till the time the time the female worm becomes pregnant.
Signs and Symptoms of pin worms
- More common in children
- More common in females
- Intense irritation and itchiness in the perianal area
- Disturbed sleep at night
- Rashes in the anal region due to scratching
- Vaginal discharge
Diagnosing pin worm
- History of perianal itchiness is one clue , then of course swabs are taken from the skin around the anus in the morning before bathing or going to the toilet and sent to a lab to check for eggs under a microscope .
- Another way is called the scotch tape method , where the sticky side of the tape is placed out and the non sticky side along one side of a tongue depressor and the sticky side is allowed to stick to the skin around the perianal skin and the sample sent to a lab where eggs can be seen on the sticky side of the tape under a microscope .
- Sometimes the eggs can also be found under the finger nails , on the surface of stools or the adult can be found crawling out at night on the skin .
Treatment and Prevention
- Several drugs like Pyrantal Pamoate , Mebendazole , Piperazone can be taken as a single dose or 2 weeks .
- Clean all bed sheets
- Cut finger nails
- Wash hands before eating
- Wear loose clothing
- Practice good hygiene
- Treat all individuals in groups