food allergy acute urticaria

Acute urticaria induced by food allergy is essentially an IgE-mediated type I hypersensitivity reaction. Most of the symptoms occur within 10 minutes to 6 hours after eating the allergenic food, with edematous wheals and severe itching as the core manifestations. More than 90% of mild patients can completely subside within 1 week without sequelae. Severe allergic reactions such as laryngeal edema and hypotension require emergency injection of epinephrine as soon as possible. There is currently no so-called "once and for all radical cure".

Last week, a sophomore girl was picked up at the outpatient clinic. She and her roommate shared half an imported mango. As soon as she returned to the dormitory, she felt numbness and itching around her mouth. She didn't take it seriously. Twenty minutes later, "mosquito bags" appeared on her arms and waist. The more they scratched, the bigger they became. She was so swollen that her roommate gave her a loratadine pill. Within ten minutes, she suddenly said that her throat was tight and she couldn't breathe. They were so frightened that several people quickly called 120 to bring her over. When she arrived, her fingertips were a little white. They gave her epinephrine to push hormones, and it took a long time to recover.

When many people talk about acute urticaria, their first reaction is "Did I eat something wrong?" But in fact, there is no unified judgment standard in the academic community to confirm whether it is caused by food. One group of doctors insists that the diagnosis must be confirmed by combining serum specific IgE testing and a positive skin prick test. The other group of doctors with more clinical experience believes that as long as the attack history is clear-that is, a rash occurs within a short time after eating the same food every time, and the possibility of infection, hot and cold stimulation, and stress-induced urticaria can be ruled out, even if the test result is negative, it can be clinically determined to be urticaria induced by food allergy.

To be honest, I have encountered too many people in the clinic who came in with "food intolerance" test reports, saying that they were allergic to rice and eggs, and had been avoiding these foods for more than half a year, and their skin was sallow and skinny. It must be mentioned here that the current domestic allergy association has already reached a consensus that food IgG testing reflects the immune exposure history of food, which is completely different from food allergy. It cannot be used as a basis for diagnosis at all. This unnecessary taboo has no benefit except torturing yourself.

Don’t panic if you encounter this situation. Look at your symptoms first. If there are just wheals and itching, but no other discomfort, just take a second-generation antihistamine. I often tell patients, don’t wait until the itching is all over the place to take it. Take the medicine as soon as you notice one or two small bumps. It will most likely be suppressed in 20 minutes. Calamine lotion can be applied, but it can only temporarily relieve the itching and cannot solve the fundamental problem of allergies. If you scratch the skin, don’t apply it as it will easily irritate the wound.

But if your throat becomes tight, your voice becomes hoarse, your stomach hurts, your vision goes dark, or you can't breathe, don't hesitate to call 120 and go to the emergency department. If you have an epinephrine pen at home, just stick it into the outside of your thigh. You don't have to wait for 120 to arrive. This thing is really life-saving. There is also controversy over whether to always have an epinephrine pen on hand: some doctors believe that as long as you have had a severe allergic reaction, you must have it on hand, while others think that it is not necessary if you just have a simple rash and no systemic symptoms. You can just discuss it with your attending doctor based on your previous attacks.

Many people automatically avoid all "foods" as soon as they get urticaria. They won't touch beef, mutton, seafood, or eggs. I once had a brother who suffered from urticaria for half a month. He didn't even dare to eat soy sauce. He lost five pounds. In the end, it was found out that he was allergic to the fragrance in the laundry detergent he bought at home. It had nothing to do with the half a cent he ate. There is really no need to blindly avoid food. You just need to recall what you ate before the onset of the disease that you have not eaten before, or if you feel a little uncomfortable after eating it before, just avoid it. As long as there is no reaction after eating other foods, you should eat it. If you cannot keep up with nutrition, you will get better slowly.

Oh, by the way, many parents ask me if their children get food allergy urticaria once when they were young. Will they be unable to eat this food for the rest of their lives? In fact, it is not necessarily true. A small number of children will gradually develop immune tolerance to allergens such as milk and eggs when they grow up, and they can eat normally in the future. If you want to confirm, you can go to the hospital for a food challenge test. Don't try blindly at home. If it induces a severe allergic reaction, the gain outweighs the loss.

Don't believe those folk remedies on the Internet that say "detoxification can cure urticaria". Most of the traditional Chinese medicine baths and bloodletting treatments charge IQ taxes. Food-induced acute urticaria is essentially your immune system's "recognition" of a certain food. If you don't touch it next time, nothing will happen. If it recurs for more than 6 weeks, you need to consider whether it is chronic urticaria. That is another question. Don't scare yourself. Just go to the allergy department of a regular hospital to see it.