Food allergy refers to the abnormal immune response of the body caused by normal eating. When non-body "foreign objects" break in, the body's immune mechanism will respond accordingly to "eliminate" the intruder. It affects life at least, but threatens life.
In summer, crayfish occupy everyone's table by the wind and waves. Some people say that the summer without crayfish is incomplete, but some people have to be careful when they want to spend the "complete" summer. Not long ago, a girl from Jiangsu developed allergic symptoms after eating crayfish-urticaria, palpitation, and difficulty breathing all over the body and was rushed to the hospital for emergency treatment!
Food allergies are becoming more common now, ranging from affecting quality of life to threatening life and health. On the occasion of World Allergy Disease Day on July 8, Liu Ruiling, the head of the Allergy Department of Tianjin Medical University General Hospital and the deputy director of the Tianjin Allergy Branch of the Chinese Medical Association, said that food allergies range from infants to young people to elderly people. It can happen, and severe food allergies can be life-threatening. At present, the best way to treat food allergies is to find the allergen in time and stay away from it.
Immune mechanism mistakes food as "enemy"
"Food allergy refers to the abnormal immune response of the body caused by normal eating." Liu Ruiling explained that when a non-body "foreign body" breaks in, the body's immune mechanism will respond accordingly to "eliminate" the intruder. When most people eat all kinds of food, the human body will digest and absorb it, and will not be regarded as an "enemy". However, for people with allergies, when certain ingredients in food enter for the first time, the body undergoes a series of "identification, screening" and other chain reactions, resulting in a specific allergy to a specific allergen. Immunoglobulin E antibody (IgE). When the food comes again next time, IgE will activate the corresponding "anti-terrorism mechanism" to respond. This "trivial" reaction will also produce some substances such as histamine, leukotriene, etc., causing local or systemic reactions in the human body, and may cause functional damage to tissues and organs. At this time, a series of allergic reactions will occur .
"Food allergies, mild symptoms can cause sudden itching of the throat, skin flushing, urticaria, and swelling of the lips; severe cases can cause life-threatening reactions such as acute asthma, throat edema, blood pressure drop, and anaphylactic shock." Liu Ruiling said , These symptoms may not all occur. The time of occurrence may be immediately after eating the food that caused the allergy, or it may be two hours later.
In theory, any food can cause allergies. Open the long "food allergy list", there are more than 400 kinds of food can cause allergies. For the Chinese, the main allergenic foods are milk, eggs, nuts (such as hazelnuts, almonds, walnuts, etc.), soybeans, wheat, seafood (such as crabs, shrimps, fish, shellfish, etc.), and some vegetables Fruits such as celery, tomatoes, peaches, cherries, apples, etc.
Although food allergies can occur in all ages, the allergens that cause food allergies vary from age to age. Among them, 62% of infants and young children aged 0-3 years old had food allergy as the first cause of milk; 59% of children aged 4-9 years were mainly caused by fruits and vegetables; young people and adults after 10 years old, wheat-induced anaphylactic shock jumped to the top, and The proportion continues to rise with age.
Liu Ruiling explained that there are many factors that cause allergies, the most important of which is the stimulation of allergens. In addition, infections, climate change, emotions, sports, and even female pregnancy can trigger allergic reactions.
A few sesame seeds can cause death
"It needs to be emphasized that foods that cause food allergies do not have any problems. They are usually high in protein and nutritious foods. The allergic reaction is caused by their own allergic constitution, which is essentially different from food poisoning." Liu Ruiling introduced that food poisoning is caused by the ingestion of food itself contaminated with bacteria or bacterial toxins, or it may be an acute toxic disease caused by food containing toxins.
Bacteria causing food poisoning mainly include salmonella, staphylococcus aureus, pathogenic Escherichia coli, etc. These bacteria and toxins stimulate intestinal peristalsis and produce intestinal cramps, causing diarrhea and abdominal pain. If the toxin enters the bloodstream, the patient will also have fever, dizziness, general malaise, acidosis, and coma.
Various toxins in poisonous mushrooms, solanine in germinated potatoes, dicolchicine produced by oxidation of Flammulina velutipes, saponins contained in uncooked string beans and other toxic substances can also cause food poisoning.
People often talk about "poisoning" discoloration, but as everyone knows, serious allergic reactions are worse than "poisoning". "Maybe a bite of peanut butter and a few sesame seeds can kill people." Liu Ruiling introduced that there was a case where an 18-year-old British boy was extremely allergic to dairy products. The restaurant had been told not to use dairy products for food, but An hour after the meal, the boy died of food allergies, and only later found that the ingredients of the roast chicken contained dairy ingredients. There is also a 15-year-old British girl who died of an allergy after eating a baguette containing sesame seeds at the airport.
The research report on the cause of anaphylactic shock in China shows that the incidence of severe allergic reactions in adults is significantly higher than that in children, and 68% of severe allergic reactions occur in 18-50 years old. Among the causes of anaphylactic shock, food incentives account for 77%. In the list of foods that induce anaphylactic shock, wheat accounts for 37% of the total incentives; fruits/vegetables rank second, accounting for 20%; followed by beans/ peanuts 7%, nuts/ seeds 5%.
What should patients with severe food allergies do if they ingest food that causes allergies? Liu Ruiling said that in foreign countries, many people diagnosed with severe food allergies will carry an adrenaline injection pen with them. According to the relevant guidelines, in an emergency, intramuscular injection of adrenaline is the first rescue method for food allergies, not hormones and anti-allergic drugs.
Pay attention to the details of daily life
As far as the current medical level is concerned, food allergies are still "incurable". Liu Ruiling reminded that once diagnosed with a food allergy, the best treatment is to avoid eating this food and any food containing this food ingredient. In order to ensure balanced nutrition, alternative foods can be selected. For children with allergies to milk, hydrolyzed formula milk powder or amino acid milk powder can be used instead of milk.
In addition, we must pay attention to some details in daily life to avoid allergies. Doctors in the Department of Allergy (Allergy) Reaction of Peking Union Medical College Hospital have reported 15 cases of "exercise-induced anaphylactic shock after eating pasta" in my country, which is medically known as "wheat-dependent exercise-induced anaphylactic shock." In other countries, there are patients with anaphylactic shock caused by exercise after eating pasta.
Therefore, experts say that people who are allergic to wheat should avoid exercise within 6 hours after eating pasta, so as to avoid food-dependent exercise and trigger serious allergic reactions.
In addition, containers containing allergenic foods and other foods may also "contaminate" subsequent foods to contain allergens, which may eventually cause food allergies.
"At present, some people are "desensitizing" through traditional "immunotherapy". Specifically, they start from a small amount and give patients food that causes allergies, and then gradually increase the dose to slowly achieve the effect of "desensitization." Liu Ruiling introduced that this method has a successful case in the treatment of food allergies, but it seems to be simple to operate, but it actually has a great risk. After all, a small dose of allergens may cause serious allergic reactions. Therefore, people with food allergies should never "desensitize" at home.
"The World Health Organization and the World Allergy Organization recommend the treatment of people who are allergic to pollen and mites. You can gradually let the allergen enter the patient's body by injection or sublingual administration. Substances are allergic." Liu Ruiling said that at present, such sublingual administration or injection methods have not been clinically applied to the treatment of food allergies. In addition, some researchers have developed a biological agent designed to inhibit the combination of IgE and allergen protein, thereby reducing allergy symptoms.
Other researchers are committed to developing foods that are free of allergens. For example, through biotechnological transformation, they operate at a certain step in the process of food from DNA to antigen generation, so that the last synthesized substance loses its "vicious ability". However, the difficulty of this method is that there are many allergens in the food, so that to keep "silence" for each kind requires too much "genetic modification". Whether the modified food can be eaten is questionable.
Our reporter Chen Xi