How do pinworms come about

Among parasites, pinworms are a type of worm that only parasitizes the human body, but how do pinworms come about? This parasite often occurs in children. It enters the stomach and duodenum through eggs, and finally enters the large intestine to become pinworms. This is a highly contagious parasite that can infect children through toys, food, and inhalation of flying worm eggs, so we must pay attention to collective infection and infection between family members.

Causes

Humans are the only host of pinworms, and people infected with pinworms are the only source of infection of pinworm disease. There are two modes of transmission: autologous infection and allologous infection. Self-infection occurs when female worms crawl through the anus at night and lay eggs on the surrounding skin, causing extreme itching. Children use their fingers to scratch the itch and become contaminated with worm eggs. Ingestion of worms while eating or sucking. The worms begin to hatch into larvae in the stomach and duodenum, and finally develop into adults in the lower small intestine and large intestine. The nymphs hatch at the anus, and the larvae can crawl into the anus and invade the large intestine, causing retrograde infection. These two modes of self-infection aggravate the infection and make it difficult to heal. Heterologous infection is through oral infection through food or toys contaminated with worm eggs, or through the mouth and nose, by inhaling flying worm eggs and then swallowing them. This is the main way of transmission between groups and families.

Clinical manifestations

About one-third of people infected with pinworms have no symptoms at all.

1. Itching around the anus or perineum

It is caused by toxic substances produced by pinworms and mechanical stimulation, which is especially severe at night, affecting sleep and causing children to cry and become restless. Due to the extreme itching, scratching causes the skin around the anus to fall off, become congested, and cause rashes and eczema. It may even induce purulent infection.

2. Digestive tract symptoms

Pinworms burrowing into the intestinal mucosa and mechanical or chemical stimulation in the gastrointestinal tract can cause symptoms such as loss of appetite, nausea, vomiting, abdominal pain, and diarrhea.

3. Psychiatric symptoms

The metabolic products discharged by the parasites in the body can cause mental excitement, insomnia, and night terrors and finger biting in children. The most common symptoms of pica in children are those in patients with pinworm infection, such as eating lumps of earth, coal slag, and salt.

4. Other symptoms

Caused by ectopic parasitism of pinworms, such as vaginitis, salpingitis, endometritis, etc. It can also invade the appendix and cause appendicitis or even peritonitis.

examine

1. Blood routine test

There were no significant changes in peripheral blood leukocytes, hemoglobin and platelets.

2. Stool examination

The positive rate of pinworm eggs in fecal examination is low, with a direct smear positive rate of only 1% to 2% and a concentrated microscopic positive rate of 5%.

3. Perianal inspection for adult worms

Because pinworms have the characteristic of crawling out of the anus at night to lay eggs, adult or female worms can be found by observing the skin folds around the anus, perineum or vulva within 1 to 3 hours after the child falls asleep.

4. Perianal examination

The eggs can be scraped, rubbed or sticked from the dirt in the perianal folds for microscopic examination. The detection rate of eggs in one examination is about 50%, and the detection rate in three examinations is over 90%. There are several methods for checking for worm eggs in the anus:

(1) Glycerol cotton swab smear method: First place the cotton swab in sterilized saline for later use. Wring out the cotton swab and wipe around the patient's anus. Then mix it on a glass slide with 50% glycerol and examine it under a microscope.

(2) The preparation method for precipitation method is the same as before. Insert the cotton swab that has been used to wipe the perianal area into a test tube containing normal saline solution and shake it thoroughly to wash the eggs into the saline solution. After precipitation, take the sediment for microscopic examination.

(3) The preparation method for cotton swab flotation method is the same as before. Place the wiped cotton swab in saturated saline, then allow the eggs to float and examine them under a microscope.

(4) Adhesive wiping method: Cut the glass paper coated with glue into small strips and then stick them on a clean glass slide for later use. Tear off the cellophane strip, stick the adhesive side around the patient's anus, then remove the cellophane and stick it back to the original glass slide for examination.