Food trigger allergies

The essence of food-induced allergies is that the immune system recognizes harmless food proteins as foreign pathogens and initiates a pathological reaction caused by an excessive immune response. In mild cases, skin itching, rashes, and gastrointestinal discomfort may occur. In severe cases, it may induce laryngeal edema, anaphylactic shock, or even death. There is currently no complete cure, but through scientific avoidance and standardized emergency response, it can be achieved without affecting normal life.

Last week, when I was working the evening shift in the pediatric emergency room, I met a mother who rushed in with her 5-year-old baby in her arms. The baby's face was so swollen that his eyes were squinted, the wind on his neck was bulging like small hills, and he was breathing so hard that it was difficult to speak even if his chest was bulging. After asking, I found out that I had been diagnosed with mango allergy before. My grandma thought that "children with allergies are squeamish, and they will tolerate it after eating less." She secretly stuffed two mouthfuls of mango ice and it became like this within ten minutes. Don't tell me, there are really many people who hold on to this idea of ​​"training tolerance" and end up putting themselves or their family members in the hospital.

Many people's understanding of allergenic foods is still limited to seafood, mangoes, and nuts. In fact, this is not the case. In the past two years, I met a high school student who was allergic to coriander. When he was eating beef noodles, two coriander leaves floated in the bowl, and his lips swelled into sausages after he picked them out. Not to mention there were cases of allergies to wheat, peach hairs, and even bayberries soaked in cold water. The immune system got angry and there was no pattern to follow.

Speaking of which, we have to mention the topic of "early introduction of allergenic foods to prevent allergies" that is currently very noisy in the academic circles. In the past, elders always said that babies should not touch things like egg whites, seafood, and peanuts before they are 1 year old, for fear of allergies. The World Allergy Organization's 2020 guidelines have really changed the statement. It is recommended that babies with a high risk of allergies (such as those whose parents have a clear history of allergies) can gradually introduce common allergenic foods in small amounts when adding complementary foods at the age of 4-6 months, which can reduce the probability of subsequent allergies. However, many clinicians have reservations, especially after seeing many children who blindly try to induce acute allergies. They feel that if the baby already has severe eczema or has a family history of severe allergies, it is best to do an allergen screening first and try it under the supervision of a doctor. Do not try blindly at home.

There is another situation that makes many people scratch their heads: I used to eat this food fine, why did I suddenly become allergic? I have a friend who has been eating crabs for more than 20 years and is fine. Last year after Yang Kang, he ate half of one. He broke out in rash all over his body, had vomiting and diarrhea, and was sent to the hospital. In fact, this situation is too common. Infection, staying up late for a long time, excessive stress, pregnancy or even the change of seasons may disrupt the originally stable immune state. The immune system that was originally at peace with food suddenly "turns its back" and regards the protein that it has tolerated for more than ten years as an intruder. To put it bluntly, it is a sign of immune disorder.

Oh, by the way, many people confuse food allergies with food intolerances, but they are actually completely different things. Allergy is a reaction involving the immune system. Even a small amount of exposure may cause serious problems. ； But lactose intolerance, such as diarrhea after drinking milk, is caused by a lack of digestive enzymes. Taking a few sips is uncomfortable but not life-threatening. Speaking of this, I have to mention the food IgG test that is very popular on the market. Many institutions sell it as an "allergen test". If more than a dozen positive results are found, people will avoid eating it. In fact, the mainstream allergy community generally believes that elevated IgG only means that you have been exposed to the food, and it is not a sign of allergy at all. Only specific IgE tests and skin prick tests are of reference significance. The final gold standard for diagnosis is food challenge test. Of course, some practitioners of functional medicine believe that long-term consumption of IgG-positive foods may induce chronic inflammation. However, there is currently insufficient evidence-based medical evidence to support this statement. Whether or not to believe it depends on personal choice. However, if you really suspect allergies, you still have to go to the allergy department of a regular hospital for an examination. Don’t trust the test kits online that cost tens of dollars. They are not accurate.

Don’t panic if you are actually diagnosed with a certain food allergy. The safest way is to avoid it completely. Don’t believe in the folk remedies of “eat a small amount and it will get better slowly”, unless you are doing oral immunotherapy in a regular medical institution. This is quite controversial now. It is true that many patients have improved their tolerance through gradual administration over three to five years. However, there is also a risk of inducing severe allergies in the process, and you must not do it blindly at home. Another special reminder: Don’t take it seriously because the last time you had an allergic reaction was just a rash that didn’t itch or hurt. The degree of allergic reaction may be different each time. This time it was just itchy skin, but next time it might lead to laryngeal edema and shock. I met a young man who was allergic to cashew nuts before. He only had rashes every time he was allergic. He was careless and didn't bring any medicine. He drank a cup of milk tea with crushed cashew nuts. As soon as he walked out of the store, his throat became tight and he couldn't speak. Fortunately, there was a community hospital nearby, and he was rescued with epinephrine. Therefore, people who have been diagnosed with severe food allergies are best to keep an epinephrine pen with them. If something goes wrong, hit the outside of the thigh as soon as possible. It is much more effective than waiting for 120 calls.

Among the allergy patients I have come into contact with, many people feel that the sky has fallen when they were first diagnosed. They can't eat this or that, and they are running out of time. In fact, it is really unnecessary. Nowadays, whether it is takeout, dine-in or pre-packaged food, allergen warnings are basically marked. When going out to eat, ask if there is anything in the ingredients that you cannot touch. Keep antihistamines and first-aid pens with you. Apart from the few things you have to go around, there are still plenty of delicious foods. After all, eating two less bites of mango crab is nothing compared to life-threatening, right?