• The wheat powder designed for the food challenge test and oral immunotherapy treatment, which must be carried out under medical supervision. Below, two types of epinephrine injectors.
  • A patient with serious allergic symptoms./Photo courtesy of Samitivej Thonburi Hospital.

When food can mean death

lifestyle October 16, 2018 01:00

By PARINYAPORN PAJEE
THE NATION

5,771 Viewed

Once extremely rare in Thailand, food allergies are becoming increasingly common, here's what you need to know about them



Two years ago, a primary school girl in Surin was catapulted into the headlines after being forced to prostrate herself at her teacher’s feet in front of hundreds of her fellow students. Her crime? Refusing to eat the egg tofu soup served as part of the school lunch having been told by her doctor that it could potentially cause an allergic reaction. Her teacher refused to believe her and ordered her to prove it by eating the egg tofu. And while this time the child was lucky and didn’t develop an allergic reaction, the results could have been very different.

The video clip of the incident went viral and the teacher was condemned for her misguided handling of the situation. But she is far from alone. Many Thais consider a food allergy a minor problem and deal with symptoms based on what their family and friends say rather than medical advice. Some even swallow an antihistamine before eating what they are allergic to. And several believe the old wives’ tale that an allergy can be cured by eating a little of the food culprit everyday until the body is able to resist.

Such behaviour is not only stupid – it could potentially kill you.

Prof Emeritus Pakit Vichyanond, director of the Samitivej Allergy Institute (SAI) at Samitivej Thonburi Hospital, is emphatic about the dangers.

Even though Thailand isn’t facing the same level of severe allergies like in the US, Europe or Australia where people die from food allergies – the well-reported case of a British teenager collapsing and dying after ingesting the tiniest trace of sesame in a sandwich – the prevalence of food allergies globally has increased by between 300 per cent and 400 per cent over the last 15 years. Here in Thailand, allergies among young children have risen from 0.5 per cent to 4 per cent.

Dr Pakit, who worked at Siriraj Hospital before his retirement, says he used to see perhaps one or two food allergy cases a year. Today, he is seeing two cases a week. 

“Many people do not understand or are not aware of the danger of food allergies. Most of them think that the symptoms are not severe, just skin rashes or other conditions that are inconvenient rather than fatal. In fact, if the allergy affects more than two body systems or leads to anaphylaxis, death might very well occur. Patients with severe symptoms of a food allergy should seek emergency treatment and be properly diagnosed by a medical specialist,” he says.

Prof Emeritus Pakit Vichyanond

The symptoms of a food allergy are one of the most common health conditions in Thailand and can be found in all age groups from infants to the elderly. More than 1,660 foods can cause allergic reactions, but eight foods account for 90 per cent of allergic reactions: tree nuts (cashews, macadamia), peanuts, eggs, milk, fish, soy, shellfish (shrimp, crab) and wheat. In Thailand, seafood is considered a major allergen in adults but wheat flour can cause severe allergies in children.

Food allergies produce symptoms that can affect five systems: the skin (hives, rashes), respiratory system (stuffy or runny nose, sneezing, asthma), gastrointestinal tract (vomiting or diarrhoea) and the neurological and cardiovascular systems (headaches, impaired breathing, shock, a drop in blood pressure). If reactions occur in two or more systems, this is anaphylaxis – the life-threatening allergic reaction that needs to be treated right away with an epinephrine (adrenaline) shot and the victim taken to hospital as soon as possible. Antihistamines have no effect on anaphylaxis.

“In the last three years, our institution is seeing more and more patients allergic to wheat flour. It can be life-threatening if a certain amount of food containing wheat flour is consumed,” says Dr Pakit.

Open since 2015, the Samitivej Allergy Institute regularly invites leading global allergy organisations and well-known allergists to analyse and share perspectives of allergy symptoms with the aim of developing an efficient treatment in Thailand. 

Last week, the honoured guests were Dr Hugh A Sampson, chairman of the Icahn Medical School at Mount Sinai Hospital in the United States and a well-known allergist-immunologist and Dr Gary Wong, the president of Asia Pacific Association of Paediatric Allergy, Respirology and Immunology who participated in the first International Samitivej Allergy Institute Symposium dubbed “Food Allergy: The State of the Art”. 

The event was organised to provide in-depth information about critical trends in food allergies that can cause life-threatening reactions and how best to clear up the public misunderstandings of the symptoms. The symposium allowed for an exchange of ideas between the global allergist and allergists from the Samitivej Allergy Institute and specialists from all Samitivej Group affiliates. 

“In the United States, we have a much larger problem with food allergies than what you see in Thailand. One of the things that’s become very clear over the last 10 years is that food allergy is really a global problem and we’re seeing an increase all over the world. While the rate in Thailand is probably at this point still under two per cent, I can assure you as time goes on you’re will see it rise just as it has in other countries,” Dr Sampson says. 

Drs Hugh A Sampson and Gary Wong

“Asia is a very special area: there are countries in which the incidence of food allergy is very high such as Japan and Singapore and countries where it is very low like Vietnam or Indonesia. Thailand is somewhere in between – not the lowest but not the highest. We are seeing a rapid change in the lifestyles of people in the Asia Pacific region including in Thailand. This happens when countries go from a rural farming type of environment to predominantly urban setting. Here, the conditions are more sterile and people eat a lot of processed food thus reducing their immunity and leading to a rise in food allergies. I hope all the lessons we have learned from North America, Europe and Australia will mean we won’t make the same mistakes that result in a very high level of allergies,” Dr Wong adds.

Wong believes that the environment is much more important than genetics in the prevalence of food allergies. “Genetics may contribute to the development of allergies but if you look at people with food allergies, for example, many of them, particularly in Asia, have no family history of food allergies or asthma. Yet migrant studies show that the children born in Asia to Asian parents who settled in Australia do not have a lot of allergies but the children born in Australia have more and worse allergies than Caucasian Australians. That is evidence that we Asians are not protected from the development of allergies and that given the right environment and exposure we will develop them,” he says.

Prof Pakit says the best way to ensure proper treatment for food allergies is to undergo diagnostic tests to find out which particular food or foods are causing an allergic reaction. When the causes of food allergies are identified, the doctor can recommend treatments to reduce symptoms and prevent allergy attacks.

One of these treatments is the Oral immunotherapy treatment (OIT) that involves administering gradually increasing amounts of the food allergen under medical supervision. “And you increase it slowly over time with the idea that you desensitise the patient. This has been done with drug allergies and through shots that introduce pollens and environmental allergens,” Sampson says. “But this treatment must be conducted under the strictest medical supervision.” 

The OIT is available at the Samitivej Allergy Institution also and treatment can take several months if not years.

“With oral immunotherapy, we can generally desensitise about 75 to 80 per cent of patients. The one downside to oral immunotherapy is there are lots of adverse reactions. Basically all the children we treat are going to experience some symptoms such as itching, itchy mouth or throat or stomach aches. About five per cent get more severe allergic-reactions,” Sampson says. 

He adds that another treatment is epicutaneous immunotherapy, which uses a patch is containing the allergen. More often than not, this contains peanut and is placed on the child’s back. The patch is replaced every day and the rate of major adverse reactions is much lower. “Though they do get itchiness and redness around the patch but not the other symptoms we see with oral immunotherapy.

“But what I need to stress is that neither of those treatments cure the food allergy. What they will do is protect patients from what we call the contamination levels. In the US where we eat peanut butter sandwiches all the time, this is not to make all these peanut butter allergic patients be able to eat large quantities of peanuts. There are many other forms of therapy that are currently in phase one trials. Some involve DNA vaccines, nanoparticle vaccines and common combinations with cytokines. These are all probably five to 10 years off but we are looking at many new ways to try and treat food allergies,” says Dr Sampson.