SINGAPORE: Swollen lips, rashes, swelling of the throat - these are some symptoms 13-year-old Tng Shih Kai has had to endure each time he accidentally eats peanuts.
"In the school canteen, even when they use the same knife for peanut butter and kaya waffles, he will get symptoms," his father Tng Yan Hui told Channel NewsAsia on Wednesday (Feb 1).
But a programme at the National University Hospital (NUH) is looking to help Shih Kai and those with such persistent food allergies.
According to NUH's press release on Wednesday, the Food Oral Immunotherapy (FOI) programme run by its team from the Paediatric Allergy, Immunology and Rheumatology division was started in August 2015 to treat children with an allergy to peanuts.
The hospital said food allergies could cause a range of effects from mild ones such as a rash to severe, life-threatening ones such as anaphylaxis. Children who are unable to outgrow their allergy after the age of five are considered to have persistent allergy.
The programme is now being expanded to treat children with allergies to cow's milk and tree nuts such as cashew and pistachio.
At least five children have finished their treatment for peanut allergy, while another 14 are currently undergoing treatment. The team has also started to treat one child with allergy to cow's milk, while the expansion to the other nut products will be rolled out in the first half of 2017, it added.
The treatment programme involves introducing a minuscule amount of food allergen which is then increased gradually.
For Shih Kai and his parents, the treatment has helped alleviate the anxiety of managing the condition.
During the first 12 years of the 13-year-old's life, Mr Tng said he and his wife had to educate their son about the types of food to avoid and examining food labels at supermarkets while constantly fretting about the boy's health.
DON'T TRY THIS AT HOME
It was in January 2016 that Mr Tng signed Shih Kai up for the FOI programme. During the first visit, the doctors assessed the latter's allergy and established a baseline threshold of reaction to peanuts.
Shih Kai then had to take a dose of peanut protein every day until the next hospital visit, at least once every two weeks, when the dosage was increased. He started out with 200mg of peanut protein, the equivalent of one peanut, but after 10 months, he could eat about 10 to 12 peanuts - the same as a Snickers chocolate bar or a peanut butter sandwich - at a time without suffering an allergic reaction.
He has since completed the programme, but still has to take the peanut allergen at least twice a week to maintain his level of tolerance.
As the programme does not involve any form of medication, some parents might be tempted to try it themselves at home but the head of the FOI programme, Dr Soh Jian Yi, strongly advises against this.
"There are two reasons not to try this at home; the first is the risk of a severe allergic reaction. The second is there is no commercially available scale that can measure such small amounts and with sufficient precision to be consistent," said Dr Soh, a consultant from NUH's division of Paediatric Allergy, Immunology and Rheumatology.