Food allergens Shanghai

Milk, eggs, wheat, tree nuts such as cashews/pistachios, crustacean aquatic organisms such as shrimps and crabs, and fuzzy subtropical fruits such as mangoes/peaches. At present, more than 300 public hospitals and community health service centers in the city can carry out special testing for food allergens, and the popularity of allergen labels in restaurants ranks first in the country.

Last week, I took my sister's 2-year-old Xiaotuanzi to the community child care center in Xuhui District for a physical examination. Because he kept rubbing his eyes and developed a rash, the child care doctor's first question was, "Have you ever tested for food allergens?" Our community can now do fingerstick blood screening for 12 common allergens. If the risk is high, you can go directly to the allergy department of Xinhua Hospital and use the green channel." When I first came to Shanghai five years ago, the community hospital might not even be able to tell clearly what the allergens were, let alone have special screening.

When it comes to allergen screening, the industry is actually quite noisy now. On the one hand, there are science popularization and children's health management organizations, all of which are shouting "early screening and early avoidance, allergies are irreversible". Several mothers around me had their babies take a full set of tests when they were just 6 months old. If they found out that they were allergic to milk, they immediately switched to deeply hydrolyzed milk powder. Many babies' eczema and diarrhea problems did get better quickly. Many parent-child restaurants and children's bakeries in Shanghai now have special sections for egg-free, nut-free meals. Even primary school lunches collect allergy information of the entire class in advance and prepare separate meals for children with allergies. This is indeed a detail that many cities in China have not yet achieved.

But if you ask the doctors in the allergology department of Shanghai's top tertiary hospitals, nine out of ten will advise you, "Don't blindly check for allergens." Last year, my colleague's baby was found to be allergic to wheat, eggs, and milk at a private institution. He followed the doctor's advice and avoided these foods for three months. His height dropped by two percentiles compared to his peers. Later, he went to Xinhua Hospital for an oral provocation test, only to find that the previous test was a false positive - the baby only contracted rotavirus during that time, and it was a transient intolerance caused by damage to the intestinal mucosa. It was not a real allergy at all, and he was starved for three months. Doctors say that in order to make money, many testing institutions now expand the scope of allergen screening to a very complicated list, including kiwi fruit, dragon fruit, and even beef and mutton. The false positive rate of commonly used serum-specific IgE tests can reach more than 30%. Most of the positive results detected by people without clear allergic symptoms have no clinical reference significance, but may easily cause unnecessary anxiety about food taboos.

As an interesting anecdote, last summer I went to the newly opened Seafood City on Tongchuan Road to eat crayfish. As soon as I sat down, the boss handed me a small sign that said, "All meals in our store contain crustacean allergens. Customers who are allergic to peanuts and sesame please inform us in advance and we will adjust the seasonings individually." I was quite surprised at the time, but later I found out after asking the boss that a little girl came to eat crayfish last year and did not say she was allergic to sesame. After eating, she developed a rash all over her body and was sent to the hospital. The boss paid her a small sum of 20,000 yuan. Since then, he has specially made this warning sign. Nowadays, catering companies in Shanghai, especially chain brands and Internet celebrity stores, basically regard allergen labels as standard equipment. After all, if a serious allergy occurs, the compensation will be quite large. In the catering guarantee of the CIIE in the past two years, there was even a special post for allergen control, which is uniquely meticulous in Shanghai.

Statistics from Xinhua Hospital’s allergy clinic in 2023 show that the detection rate of food allergies among Shanghai children is about 12.7%, which has doubled from 10 years ago. The doctor said there are many reasons. One is that imported food is now popular. Avocados, kiwis, and cashews, which were rarely eaten by Shanghainese people in the past, are now common snacks, and they are exposed to many more types of allergens than before. ； Another is that everyone's awareness of allergies has improved. In the past, when I had a rash or diarrhea after eating something, I thought it was a gastrointestinal damage, but now I know it may be an allergic reaction.

In fact, I think it’s a good thing that Shanghai is taking the lead when it comes to food allergies, but there are indeed signs of excessive anxiety. I read a little red book by a Shanghai mother before, saying that her baby was found to be weakly positive for tomatoes, and she was not even allowed to touch ketchup. She watched other children eat French fries and cried for half an hour, which made me feel a little uncomfortable. In the final analysis, allergen testing is only a reference. The real diagnosis must be based on actual symptoms. There is no need to spend your life just for a plus sign on the test sheet. Of course, if you really have a clear history of allergies, asking more questions when you go out to eat, and labeling the restaurant more often will save you a lot of trouble.