What reason is food allergy?

summary

Food allergy is a reaction of human immune mechanism to foreign body. When a "foreign body" enters the human body, the immune mechanism of the human body will respond accordingly and "eliminate" the invader. And allergy, because the body to "foreign body" reaction is too intense. What reason is food allergy? Let's talk about it

What reason is food allergy?

Digestive tract allergens are mainly food allergens. These foods contain a large number of antigen substances, which are constantly presented to the body's mucosal immune system for sensitization. Generally, the allergenic components in food have the following characteristics: 1) most of them are water-soluble glycoproteins; ② The molecular weight is between 10 Ku and 65 Ku; ③ Most of them are stable to heat and acid. There are thousands of foods that can cause allergic symptoms. Through food provocation test, it is found that the most common allergens are milk, eggs, peanuts, beans, fish, shrimp and wheat.

Food allergy is related to genetic factors: if one of the parents has a history of food allergy, the prevalence rate of their children is 30%. If both parents have the disease, the prevalence rate of their children is as high as 60%

The nonspecific and specific mucosal barrier system of human gastrointestinal tract can limit the invasion of complete protein antigen, and the food antigen entering the intestinal tract combines with secretory IgA (sIgA) to form antigen antibody complex, which limits the absorption of food antigen by the intestinal tract, thus directly or indirectly reducing the immune response to food protein. Children's gastrointestinal mucosa is tender, vascular permeability is high, and gastrointestinal barrier function is poor. Various food allergens are easy to enter the blood through the intestinal mucosa, causing allergic reactions. The level of IgA in infants less than 3 months old was low, and the number of SIgA producing plasma cells in the perimucosal layer was less. When the process of digestion, absorption and mucosal immunity are abnormal, all kinds of food allergens are easy to enter the blood through the intestinal mucosa, resulting in allergic gastroenteritis.

matters needing attention

Some foods do not have to be eaten. Even if they are only touched, they may cause skin itching and swelling allergic reactions, such as bananas, avocados, kiwifruit, chestnuts, papaya, pineapples, peaches, figs, potatoes, cherries, grapes, celery, tomatoes, carrots, wheat, hazelnuts, even apples and pears.