cold food allergy

The discomforts associated with cold foods that everyone often talks about as "diarrhoea, swollen mouth, and rhinitis occur when eating cold foods" are essentially IgE-mediated (type I) or non-IgE-mediated allergic reactions induced by low temperature or the ingredients of the food itself, and some belong to the category of food intolerance. Currently, there are obvious differences in the definitions and diagnosis and treatment logic of such problems between Chinese and Western medicine, and there is no absolutely unified standard answer.

Last week I met a 16-year-old girl at the allergy clinic. She showed off two popsicles while going to the night market with her classmates during the summer vacation. Within half an hour, her upper lip swelled up and she sneezed more than 20 times. Her chest felt tight and her parents were so frightened that she sent her to the emergency room. IgE tests for conventional food allergens were all negative, and the final diagnosis was confirmed by a cold challenge test - it was a contact allergy induced by low temperature. It had nothing to do with the milk or sugar added to the popsicles. Even if she ate pure ice cubes, she would most likely have a reaction.

There is actually no clear classification of "cold food" in the Western medicine system. Doctors tend to divide the discomfort associated with low-temperature food into two categories: one is the cold contact urticaria/rhinitis just mentioned, which is a type of physical allergy. Low temperature is the "switch" that triggers the immune response. When it comes into contact with the skin and mucous membranes, it induces mast cells to release histamine, causing symptoms such as redness, itching, and nasal congestion.； Another more common type is that the intestinal barrier itself is weak. After ice food enters the stomach, the intestinal smooth muscle is spasmed by cold, and the intestinal immune cells are in a state of stress. The ice watermelon or ice milk tea may have some fungal spores or uninactivated bacteria in the refrigerator, and the immune system directly "sounds the alarm", which will induce diarrhea and abdominal pain. Many people mistakenly think that they are "allergic to watermelon", but in fact, eating it at room temperature will not cause any problems.

What’s interesting is that Chinese medicine’s judgment on such issues is entirely based on a different set of logic. There is no concept of "allergy" in traditional Chinese medicine. The discomfort after eating cold food is classified as "cold evil invades the body, the defense qi is not solid, and the spleen loses its transport" - to put it bluntly, your own "protective layer" is not thick enough. After eating cold food, it disrupts the normal flow of qi and blood, so various problems occur. The direction of conditioning is also very unified: to warm the yang and stabilize the surface, such as boiling water with dried ginger and astragalus to drink, moxibustion on Zhongwan and Zusanli, and avoiding foods with cold nature and flavor such as crabs, pears, and iced drinks. I have met several patients who developed urticaria after eating ice cream. They could suppress it by taking antihistamines, but the symptoms would occur as soon as they stopped. After two or three months of treatment with traditional Chinese medicine, they were able to prevent the urticaria from occasionally eating ice cream in the summer. Western medicine has not yet found corresponding evidence-based medical evidence. It is more classified as "immune improvement brought about by lifestyle adjustments", but it will not directly deny the effectiveness of this program.

The most controversial topic nowadays is, "Am I allergic to cold foods, or am I simply allergic to spleen and stomach?" ”In fact, there is no need to harden the definition. You can do a small test yourself: if you eat iced drinks at 0℃, there will be problems, but drinking cold drinks at 20℃ or eating watermelon at room temperature will be fine. Then it is most likely a physical allergy induced by low temperature. Try not to touch things that are too cold. If it is serious, prepare some antihistamines. ； If you still get diarrhea and rashes even if you eat crabs, pears, and purslane at room temperature, which are foods classified as cold by Chinese medicine, then you are either allergic to the ingredients of these foods, or you have a cold constitution according to Chinese medicine. You can try both conditioning logics, whichever one works.

It is important to mention that if you not only have diarrhea and rash every time you eat cold food, but also have difficulty breathing and tight throat, regardless of whether it is controlled by traditional Chinese medicine or western medicine, go to the hospital for a complete allergy assessment first, and carry an epinephrine pen with you. This kind of severe allergic reaction can really kill people, so don't rely on folk remedies to treat it.

In fact, after I have come into contact with such patients more often, I feel that there is no need to argue between "allergy" and "spleen and stomach deficiency". Medicine itself is evolving, and many things that cannot be explained now do not mean they are useless. Eat less iced food in summer, and don't drink a large glass of iced milk tea just to cool yourself down. It's not a bad thing for people with allergies or people with normal constitutions, right?