SINGAPORE - A woman was sent to hospital after eating a dish containing shellfish - an ingredient which she had told the wait staff of a restaurant that she was allergic to.

Ms Chee Huijin, a 27-year-old graphic designer, had symptoms including itchy skin and swelling of the eyes. She was put on an intravenous (IV) drip and given antihistamine injections in hospital.

Doctors warn that even pinpoint specks of an allergen are enough to trigger an allergic reaction which, in severe cases, can sometimes be fatal.

In a Facebook post on Sunday (June 17), Ms Chee wrote that she visited the Soup Restaurant branch at Jurong Point with her parents earlier that day.

She told the restaurant staff that she was allergic to seafood and asked for dishes which did not contain any.

When they were served a spinach dish, the waiter reassured her that it did not have any seafood.

However, after a few mouthfuls, Ms Chee felt "weird" and noticed shreds of an ingredient that looked like scallop. When asked if it was scallop, the waiter denied and said it was shredded egg.

By this time, Ms Chee began to feel uncomfortable and her skin felt itchy. Her eyes were also starting to swell.

She asked another waiter about the dish but her inquiries were brushed off.

It was only on her fourth inquiry with a waiter, when she emphasised her allergy to shellfish, that the waiter finally checked with the kitchen staff.

"The waiter came back and said 'oh they put a little bit inside only'," wrote Ms Chee.

By this time, her heart was racing and she was unable to respond.

Her mother took her to the nearest clinic and when her condition did not improve, she was taken to the Accident and Emergency department of Ng Teng Fong General Hospital. She returned home four hours later.

Ms Chee told The Straits Times that it was not the first time she had been in such a situation. "There are cases where the server is misinformed or they do not know it can be serious, so they brush it off."

Said Dr Soh Jian Yi from the National University Hospital: "A tiny amount - such as a utensil contaminated with less than one milligram, equivalent to a few pinpoint specks' worth of the allergen - can trigger an allergic reaction, which in turn can be severe."

It is "a classic human behaviour to brush aside what we do not know much about", added Dr Soh, a consultant in paediatric allergy, immunology and rheumatology.

Food vendors, he said, should also take precautions, such as educating their staff and reminding them not to be dismissive of customers' concerns.

Dr Daniel Soong, a general practitioner at Unihealth Clinic, agreed, adding that the "bulk of the cases of food allergies could be avoided through patient education".

He encouraged the public to be aware of the symptoms of an allergic reaction in others, such as rashes, itchiness and puffiness. More severe symptoms include throat and airway swelling, which results in breathing difficulties.

Dr Soong told The Straits Times that individuals with a history of severe food allergy can carry with them an EpiPen, which is an injectable pen that treats severe allergic reaction.

Members of the Soup Restaurant management team visited Ms Chee and her parents at her home to express their regrets.

The restaurant is looking into redesigning its menus to highlight any ingredient in each dish that may trigger an allergic reaction. It will also conduct regular staff training to increase understanding of food allergies.

Although the restaurant refunded her dinner bill and paid for her medical costs, Ms Chee said: "It's not about blaming the restaurant and demanding for compensation, but about raising awareness".

She hoped her incident will make food vendors more cautious.

"I'm considered lucky to end up on a bed at A&E. There are people who die from this."