Oxyuriasis (pinworms): symptoms and treatment
Oxyuriasis is caused by an infection with the pinworm. Some doctors also call the infection with the intestinal parasites enterobiasis. The name is derived from the Latin name of the worm: Enterobius vermicularis.
Parasitic diseases are usually a rarity and often a travel souvenir from the tropics. One exception is oxyuriasis, which also occurs frequently in developed countries like the United States. About 400 million people worldwide are infected with pinworms.
The pinworms (Enterobius vermicularis) often remain unnoticed for a long time, as no symptoms are apparent. The most common and specific symptom of oxyuriasis is itching of the anus and vagina. Since the female worms usually emerge from the anus at night to spread their eggs in the folds of the surrounding skin, the itching is particularly annoying at night. When inspecting the chair or underpants, small worms are sometimes discovered. The patient usually visits the doctor for these two reasons.
A behavioural or developmental disorder may be noticeable in young children. Because of the itching, sometimes sleep disturbances occur indirectly. In girls and women, there is a risk that the worm attacks the female genitals and triggers an inflammatory reaction there. In very severe cases of infestation, inflammatory processes in the intestinal wall rarely occur. Such processes can end in appendicitis or a perforated (burst) intestine. If the patient does not react quickly in such situations, there is acute danger to his or her life. In general, however, enterobiosis / oxyuriasis is a harmless disease and complications are very rare.
Oxyuriasis: causes and risk factors
Pinworms are more common in babies and children, but sometimes also in adults. Women are generally more affected than men. The pinworm is a small, thread-like parasite that belongs to the nematodes (fade worms).
As parasites, they belong to the group of living beings that live in another organism (for example, in humans) and feed at the expense of the latter. The pinworm only infects humans. The adult worms live in the large intestine, where they develop from larvae into adult worms.
The male is about half a millimeter, the female up to 1.5 centimeters tall. After fertilization, the female migrates to the anus and lays up to 10,000 eggs in the skin folds directly around the anus, preferably at night. This causes itching, which quickly gets the eggs to the hands and under the fingernails of the infected person. If the contaminated fingers are put in the mouth, a self infection is possible.
In addition, the eggs are transferred to objects during the preparation of food or by hand contact. Since the eggs remain infectious for up to three weeks in a humid environment, even after successful treatment, a renewed infection is possible through remaining eggs. At body temperature, the worms begin their larval development in the freshly laid eggs after only a few hours. After five to six weeks the worms are sexually mature and start producing eggs.
Oxyuriasis is transmitted especially via hand contact. An important risk factor is therefore poor hygiene and careless hand washing. Since the infection occurs mainly in small children, the risk of oxyuriasis infection is higher in day-care centres or nurseries than at home. The parasite can also be transmitted during sexual intercourse. Anal-oral practices in particular make infection possible.
Oxyuriasis: examinations and diagnosis
For the doctor, anal itching is often the first sign of a possible oxyuriasis infection. The first point of contact is usually the family doctor. The latter will first interview the patient in detail. He might ask questions like:
- When does itching mainly occur?
- Have you observed white worms in the feces or anus?
A blood test can provide further evidence of a pinworm infestation. There, some immune cells that specifically fight against parasites, so-called eosinophils, are found in increased numbers. If their number is increased, one speaks of eosinophilia.
The best method, however, is the microscopic detection of the eggs early in the morning, before cleaning or defecation. This is usually done with a transparent adhesive film that is stuck to the skin around the anus. The adhesive strip is carefully removed and placed on a slide. The eggs can be detected directly with a microscope.
In some cases, especially in cases of severe infestation, the small white worms can already be seen on the stool. If the worms reach the outside world, they die quickly. In the excreted stool, however, they can sometimes still be seen in a living form. Especially the females stay near the anus. They can be recognized by their white, thread-like form and by their whip-like movements.
If an infestation with pinworms has been detected or if an infection is suspected, some points should be observed to get rid of the parasite infestation as quickly as possible. In order to avoid immediate reinfection, some hygiene measures must be taken. At the same time, drugs are administered to kill the worms in the intestines.
Hygienic measures for oxyuriasis (enterobiasis)
In order to avoid further spread and reinfection, the following instructions should be observed. In particular, mobile phone hygiene must be observed.
- Wash your hands thoroughly after going to the toilet and before contact with food
- Only disinfectants containing chlorhexidine effectively kill the eggs. Thorough hand washing is usually sufficient, however.
- Wash underwear, pyjamas and bed linen with boil wash.
- Change underwear every night.
- Tight underpants during the night prevent unconscious scratching.
- In case of anal itching apply cream before going to bed: (e.g.: Skinsept mucosa)
- Cleaning of toys and possible contaminated objects with hot water
- Keep fingernails short.
- Cleaning agents containing biguanide and phenol are suitable for cleaning surfaces.
- Household vacuum cleaners only distribute the eggs.
Drugs for oxyuriasis (enterobiasis)
The treatment of oxyuriasis is very simple. A single tablet is usually sufficient to kill the pinworms in the intestines. Since reinfections are frequent, the therapy should be repeated after 14 days. All infected persons should start drug therapy at the same time to avoid repeated mutual infection. Often people living close by, such as family members, are also treated as a precaution. There are various drugs that successfully kill pinworms. This group of substances is called antihelmintics. The two most commonly used drugs are:
Oxyuriasis: course of disease and prognosis
Oxyuriasis is usually harmless. Only rarely do complications arise. Especially in children, it is common for them to reinfect themselves the same night. By finger/thumb sucking the eggs get on a direct way from the anus to the mouth.
The therapy is very well tolerated and side effects occur only in very few cases. Complications are also rare. In this way, the worm eggs can enter the vagina and develop there. This triggers an inflammatory reaction, which can be associated with pain and possibly discharge. In case of severe infestation, intestinal function may be restricted and inflammation or perforation may occur. These potentially life-threatening courses are very rare, and are accompanied by stool retention or abdominal/abdominal pain. Oxyuriasis is a very common, easily treatable childhood disease, but it does not pose a major risk to the child’s health.