Eggs of pinworms are elongated, have a smooth double-contour light shell, in the center of which larvae are located. Pinworms (usually up to several thousand specimens) parasitize in the upper part of the large intestine, the appendix and in the lower part of the small intestines. Here they stick to the mucous membrane, sometimes they penetrate deep enough into the liberkune glands.
It is known that the uterus of a fertilized pinworm contains about 1,200 eggs. The males die after fertilization of the females, and the females move to the lower parts of the colon into the rectum and, leaving the last, lay a large number of eggs in the folds around the skin of the anus, and they die. When scratching the perineum around the anus, the eggs fall on the fingers, under the nails, from where they can enter the food and mouth and cause reinfestation.
Infection also occurs through fecal masses containing pinworm eggs. Eggs laid in the perinatal region are not quite mature. They ripen for 6-7 hours at a temperature of 36-37 degrees Celsius. Below 22 degrees, ripening does not occur, however, mature eggs at room temperature remain viable for a month. They can be found in the dust of the floor, walls, window sills, cabinets, in classrooms.
When penetrating the thickness of the intestinal mucosa, pinworms can contribute to the introduction of intestinal bacterial flora into the tissues of the body with the development of inflammatory changes in them, as well as catarrhal and purulent appendicitis. Pinworms can cause cracks in the anal area due to scratching, suppuration of these cracks. Sometimes there are rash, eczema caused by irritation. prolonged and painful itching in the perineum can lead to the fact that patients, especially children, become nervous, capricious, they lose their appetite, sleep is disturbed, night-time urinary incontinence appears. The painful itching of the perineum in women is accompanied by psychasthenia, a decrease in working capacity. In girls, irritation with pinworms of the genitals leads to an early manifestation of sexual desire.
The diagnosis of enterobiosis is established on the basis of complaints of patients, indications of creeping pinworms and if parasites or their eggs are found in the feces or in the anus. Pinworm eggs can also be found in the subungual spaces.
For prevention, it is necessary to meticulously handle the hands after the toilet, in the morning and before eating. Wet cleaning should be done periodically to prevent eggs from dispersing and breathing in dust.