Children are prone to food allergies, and effective identification and emergency symptomatic treatment are crucial!

Author: Wu Jie, Chief Physician, National Children's Medical Center, Beijing Children's Hospital, Capital Medical University

Reviewer: Yang Yunsheng, Chief Physician, PLA General Hospital

Food allergy in children is an IgE-mediated and non-IgE-mediated immune response caused by certain foods or food additives, which leads to skin, digestive system or systemic allergic reactions. The incidence rate is increasing year by year.

There are eight common allergenic foods for children. The most common is milk, followed by eggs, nuts, peanuts, fish, shrimp, wheat and soybeans.

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1. Why are children more prone to food allergies?

First of all, it is related to the immature development of multiple systems in children, especially the immature immune system. Certain foods entering the body will trigger abnormal immune responses; the intestinal barrier function is immature, and many large molecular foods can pass through the intestines directly into the blood, causing allergic reactions; the immature or imbalanced intestinal flora also has a certain promoting effect on the occurrence of food allergies.

It is now found that there are many high-risk factors for food allergies in children, such as heredity. If one of the parents has a history of allergies, the risk of allergies in children under one year old is about 40%; if both parents have a history of allergies, the risk of allergies in children under one year old increases to 80%.

In addition, babies born by cesarean section are more likely to have allergies than those born naturally. Insufficient vitamin D supplementation can also easily lead to allergies. The timing of adding complementary foods is not appropriate. The later the complementary foods are added, the more likely allergies will occur. The most appropriate time to add complementary foods is 4-6 months old. If a child is exposed to highly allergenic foods within one year old, the probability of the child having food allergies before the age of five will be higher.

In general, the immaturity of multiple systems in children, coupled with various high-risk factors, make them relatively more susceptible to food allergies.

2. What are the symptoms of food allergies in children?

Food allergy is a systemic immune inflammatory response, often manifested in multiple systems. If the symptoms manifest as a single system, such as symptoms of the digestive tract or skin, you should look for other causes, it is likely not caused by allergies.

The organs most commonly affected by food allergies are the skin and gastrointestinal tract. 50%-60% of children will have skin manifestations, mainly eczema, urticaria, and skin itching; angioedema, manifested as edema of the eyes and lips.

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Among children with food allergies, the incidence of gastrointestinal symptoms is as high as 50%-60%, but the symptoms are not specific and may manifest as aversion to milk, that is, a sudden loss of appetite; retching, nausea, gastroesophageal reflux; abdominal distension, intestinal colic; changes in stool, manifested as diarrhea, constipation, difficulty in defecation, stool with mucus and blood, etc. If a child continues to have gastrointestinal symptoms and does not gain weight, it is highly suspected that the child is suffering from food allergies.

20%-30% of children may have respiratory symptoms, mainly repeated nasal congestion, coughing, and wheezing. Many parents initially thought their children had a cold, but anti-infection treatment did not improve. Chronic coughs should be considered to be caused by allergies.

Other systems may also show symptoms, such as the nervous system. Children may be more irritable, and older children may have some cognitive problems and hyperactivity.

3. Under what circumstances does a child with food allergy require emergency medical attention?

Children's food allergies are divided into immediate reactions and delayed reactions. Immediate reactions cause symptoms within two hours of eating a certain food, while delayed reactions cause symptoms more than two hours after eating a certain food, or even several days later.

If a child shows symptoms, it is highly suspected that they are caused by food allergies. Rapid allergic reactions require prompt medical attention because the symptoms may be more serious. For example, allergies may cause laryngeal edema, difficulty breathing, and obvious wheezing; or particularly severe vomiting may occur, which may be accompanied by dehydration in the early stages. The child's mental state suddenly deteriorates. Failure to receive timely treatment may lead to coma, shock, and may even be life-threatening.

If a child has a severe immediate allergic reaction, before the arrival of 120 or before being sent to the hospital, for example, if the vomiting is particularly severe, you should provide vomiting care, let the child's head tilt to one side, or hold the child upright to avoid suffocation caused by vomiting; if the diarrhea is particularly severe, give the child antidiarrheal drugs and oral rehydration salts first to avoid severe dehydration before admission to the hospital; if angioedema occurs and the eyes are severely swollen, you can try to give the child some anti-allergic drugs, treat the symptoms initially, wait for the arrival of 120 or send the child to the hospital urgently.

If it is a delayed allergic reaction, the allergic reaction occurs relatively slowly, or the child's symptoms are relatively mild, such as a little diarrhea, some crying, or a little urticaria on the skin. You can stop the suspected allergenic food and observe it first, or you can use some medications according to the symptoms. For example, if diarrhea occurs, you can take montmorillonite, probiotics, and rehydration salts; for skin allergies, you can use some anti-allergic drugs, and consider going to the hospital if the symptoms do not improve.