Think your child has food allergies? Think again

SINGAPORE - Many parents are needlessly cutting out food such as nuts and milk from their child's diet for fear that eating such products will spark an allergic reaction.

A study by National University Hospital (NUH) found that most children thought to have a food allergy do not have one. From 2008 to 2010, the hospital put 58 children with a median age of six through 197 "food challenges".

This is a test that is done under the supervision of medical staff to determine which food, and how much of it, can spark an allergic reaction in a person.

In the study, the children were given items that they had avoided for a variety of reasons. These include a belief that they were allergic to them and results of previous medical tests which showed that they had a food allergy.

But the children passed nearly all the tests - results of 95 per cent of the food challenges, which featured nuts, egg, milk, soya and fish, turned out to be negative.

Only 10 children had mild reactions which were easily treated with antihistamine medication.

WRONG ASSUMPTIONS

This means that most of the time, the food items were being unnecessarily avoided, said Associate Professor Lynette Shek, who heads the division of paediatric allergy, immunology and rheumatology at NUH.

"The perception is high, but the reality is low," said Prof Shek, who led the study.

One problem, she said, is that parents often link a wide array of symptoms to an allergy.

For instance, a child may vomit or develop a headache after eating something.

Some parents may blame such observations on an allergy when it may not be the case. In fact, an allergic reaction often triggers not just one but several symptoms at the same time.

For instance, the person may be hit with a combination of rashes and breathing difficulties.

In another common scenario, a child with an allergy to peanuts may be asked to avoid all kinds of nuts too, said Prof Shek.

While many children tend to outgrow their allergies, the fear can still persist, she said.

"Imagine someone telling you for years that if you eat a peanut, you will die."

She cited a teenage patient who, as a young child, had an allergic reaction to the peanuts found in a banana-split dessert.

Although she was not allergic to bananas, she avoided eating them and would even cry at the sight of the fruit.

Food allergies come in different forms. Some can be serious and cause a drop in blood pressure, while others can cause inflammation of the food pipe and swelling of the lips. Symptoms can arise shortly after eating the problematic food.

In some instances, however, the reaction can be delayed by several hours or even days.

WHEN TESTS ARE UNRELIABLE

It is unclear why people suffer from such food allergies.

Adding to the problem is that allergy tests, such as skin-prick tests, are not always accurate.

Mrs Cindy Tan, 42, said she had been hesitant to let her nine-year-old son try new types of food partly because of the unreliability of skin-prick tests.

Her son, Sage, had twice tested negative for allergy to peanuts in 2011. But when she gave him a peanut butter sandwich two years ago, rashes started appearing around his mouth and he had to seek medical help.

Sage had tested positive for a string of allergies when he was younger, including salmon, tuna, scallops, walnuts and prawns.

The family found out that he had been needlessly avoiding all these foods after Sage passed six food challenges at NUH last year. He had a reaction only to egg white.

"Sometimes, it can get a bit confusing," said Mrs Tan, who has an older son aged 13.

The findings of the NUH study have been submitted to the Asia Pacific Allergy Journal for publication.

The study has prompted the participants' parents, such as Mrs Tan, to reintroduce food items into their children's diets and to remove the food allergy labels the kids carry with them.

Prof Shek emphasised that caution is needed if the child has a real allergy, but the condition is not always a lifelong burden.

"I hope that parents can realise that there is no need to continue living in fear and anxiety," she said.

chpoon@sph.com.sg


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