Infestation with pinworms is very common. It occurs in many countries around the world and it is estimated that more than 40 million people get infected with pinworms in the United States each year. Infestation with pinworms predominantly affects children. The most common symptom of pinworms is itchiness of the rectal area. The symptom is most intensive during night. At night female worms are most active and they crawl out of the anus in order to deposit their eggs.
Causes of Pinworms in Humans
Pinworms spread thanks to tiny eggs that are found in the anal area. Each adult female pinworm is able to produce 10.000 eggs during her life. Itching of the anal area leads to scratching of the affected skin and the eggs may lodge under fingernails. In case a person does not take care of hygiene and does not wash hands frequently (especially after scratching of the anal area) there is a chance of parasite transmission. Parasites can be also spread via infested clothes, bedding or toys. Only if these eggs are ingested the infestation develops.
Once the eggs have been ingested they hatch and the worms slowly maturate. They migrate towards the junction between the small and large intestine where they develop into adult worms. After female worms reach sexual maturity they become able to produce eggs and start to to come out from the anal canal at night and lay eggs.
Symptoms of Pinworms in Humans
In many people infestation with pinworms is asymptomatic. However, if symptoms or signs of the infection do occur they are in a form of intensive itching around the anus. The person scratches the affected area and this may cause cracks in the skin and secondary bacterial infection.
In rare cases pinworms may migrate into the vagina or the urinary tract and cause irritation. Even if this does occur the leading symptom is severe itching sensation.
Pinworms never cause abdominal pain, bloody bowel movements, fever or loss of appetite.
Treatment for Pinworms in Humans
These worms require medicamentous treatment. Only certain medications are able to eradicate parasites from the intestinal tract. The most commonly prescribed medication for pinworms is abendazole. The treatment includes intake of a single tablet. The dose differs depending on the age of the patient. Since eggs may survive for a few weeks the second dose of the medication is generally taken two weeks later. The dose prevents reinfection. One more medication effective against pinworms is mebendazole. It is also administered in a single dose with the repeated dose after two weeks.