A child receives a skin prick test at Peking Union Medical College Hospital on April 28 (WANG HAIRONG)
Every day at noon, while other children in his class get ready for lunch at their kindergarten in north Beijing, Ruiyang has to go back home.
"Because of his food allergy, we have to take precautions. Exposure to the wrong food can cause trouble," said Qi, his mother, an IT professional in Beijing.
Ruiyang, 6 years old, has suffered from chronic eczema since he was 3. "In the beginning, we suspected an allergy to pollutants from interior decoration because we moved to a new apartment," Qi said.
Qi brought her son to a number of hospitals including the Allergology Department at Peking Union Medical College Hospital. Ruiyang was subjected to numerous tests, and eventually doctors deduced that he is allergic to wheat.
On the rise
Food allergy is the overreaction of the body immune system to harmless macromolecular substances in food, usually protein. During an allergic reaction, the body's immune system produces abnormal or incorrect responses, explained Yang Ling, a doctor with New Century International Children's Hospital located in west Beijing. Yang said that the most common types of food triggering allergies are milk, nuts and seafood.
A random sample study conducted in Panzhihua, southwest China's Sichuan Province, showed that 7.58 percent of local children aged 0-3 suffered food allergies from 2010 to 2012. The study identified cases of allergies through questionnaires and physical examination.
There are about 20 children in Ruiyang's class, and two of them suffer from a food allergy.
In the United States, the U.S. Centers for Disease Control and Prevention (CDC)'s website cited studies showing that food allergies affect 4 to 6 percent of children in the country, with the prevalence of food allergies among children increased 18 percent during 1997-2007. Though symptoms can appear at any age, they are most common in babies and children.
According to estimates by Chinese doctors, reported by Guangdong-based Southern Weekend, 10 million or about 10 percent of Chinese children aged 0-6 suffer from various degrees of food allergies.
"I have worked as a doctor in the allergology department for more than 30 years. In the 1980s, I received fewer than 100 allergy patients a year. In the last three years in a row, I treated more than 30,000 patients every year. That is a 300-fold increase," Liu Guanghui, Director of the Allergic Reaction Department of Tongji Hospital in Wuhan, capital city of central China's Hubei Province, told Wuhan Evening News.
Xu Pengfei, Deputy Director of the Department of Pediatrics in China-Japan Friendship Hospital in Beijing, told the Southern Weekend that he has paid attention to children's allergies since 2001. Now he received 1,400 allergic children every month, and he estimated that 10-15 percent of them are allergic to food. He said that half of these children allergic to food suffer from recurrent symptoms of an allergy.
A food allergy is not easy to diagnose. The symptoms are often mistakenly treated as diseases such as pneumonia and enteritis, with a large dose of antibiotics--which in turn trigger more serious allergic reactions.
Allergy can cause skin, gastrointestinal and respiratory problems, said Zhi Yuxiang, a doctor in the Allergology Department of Peking Union Medical College Hospital. Severe allergic reaction may cause shortness of breath, a coma and even death.
A girl named Dongdong almost lost her life to food allergy when she was 13 months old, reported Southern Weekend. After eating a mixture of fruit puree and meat puree, Dongdong had a serious rash, and then a serious brain disease caused by virus. She was struck by a seizure and lost consciousness.
The girl, now 4 years old, can only eat five types of food, vegetable puree, beef puree, corn puree, amino acid paste and amino acid yoghurt powder. She is vulnerable to infection, and has been hospitalized for many times. Her illness has deeply upset her mother and strained the family's finances.
Causes and treatments
As to what causes allergies, Zhi said that it is not only inheritable but can be compounded by environment factors.
Liu believes that modern urban lifestyle contributed to increasing prevalence of allergy by exposing people to more triggers. For instance, people used to wear home-spun cotton clothes, while now they mainly wear clothes made from synthetic fibers. They ate simple food before, whereas now food has become assorted and complicated. In addition, modern decorative materials in buildings and cars also emit toxic volatile substances, and stress can also sensitize people's immune system to allergens, Liu said.
Liu also cited a U.S.-based study in 2013 asserting that children delivered by cesarean section are significantly more likely to suffer from allergies.
Some researchers also suspect that nowadays, people grow up in a clean environment, so they have fewer chances to come into contact with microbial, and such lack of contact can affect the development of their immune system.
As to how to treat food allergies, Zhi said that currently, it is very important to avoid allergens. For instance, if a child is allergic to milk, then he or she better not to drink milk or eat any food containing milk.
Zhi's suggestion is echoed by a tip posted on the website of the U.S. CDC, "There is no cure for food allergies. Strict avoidance of the food allergen is the only way to prevent a reaction."
Liu said that inhalant allergy can be treated with desensitization therapy, while in cases of food allergy and contact allergy, it is important to identify allergens and avoid them as much as possible.
Zhi said that two major ways to identify allergens are skin and blood tests. In a skin prick test, a suspected allergen is put on the skin, and the skin is scratched or pricked, to see if an allergic reaction appears. In an intradermal test, the allergen solution is injected into the skin. A blood test is to measure the level of an antibody called immunoglobulin E, which the body may produce in response to certain allergens.
While avoiding allergens is recommended by doctors, some parents have tried more active steps to desensitize their children to food.
"Many parents would like to get children used to certain food by asking them to take a bite at a time, and then add portion gradually, yet this practice is quite dangerous," Liu said. Sometimes, a bite of a trigger food may cost a life, he warned.
He said that if parents want to try this desensitizing therapy, they should ask doctors to evaluate the risks, and the therapy must be administered in a hospital under the doctors' supervision. He noted that to his knowledge, there is no hospital in China that offers such desensitization therapy to address food allergy.
Copyedited by Kieran Pringle
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