She had given her baby less than a spoonful of rice cereal. But six-month-old Zoe showed signs of breathing difficulties.

Ms Jenny Huang (right, with Zoe) could tell her daughter was choking and breathless, from the tears that were forming in the baby's eyes. In a panic, she called for an ambulance and ran out of her condominium, carrying her baby in her arms. The child was turning blue.

Ms Huang was living in San Francisco at the time. Luckily, the ambulance arrived in just two minutes.

Paramedics made a quick assessment and gave Zoe a shot of epinephrine, which saved her life.

It was only later that Ms Huang learned that Zoe had experienced a life-threatening allergic reaction to the dairy content in the rice cereal.

Fatal reaction to food

A food allergy is the reaction caused when the immune system mistakenly identifies a normally harmless food as damaging to the body.

Consultant paediatrician Lee Bee Wah, who runs The Child and Allergy Clinic in Singapore, said the severity of immediate food allergic reactions can range from mild - such as rashes and itchiness of the mouth - to severe and life-threatening - such as choking, breathing difficulties and a severe drop in blood pressure, like the one Zoe suffered.

This is called anaphylaxis and can be fatal unless treated by an injection of the hormone epinephrine, which stops the chain of reactions.

Zoe survived her anaphylactic reaction because the paramedics gave her this injection immediately.

She is now six years old.

And in this short time, her parents have found that she is allergic to a long list of food besides dairy products.

These include eggs, wheat, peanuts, tree nuts, melons, beans, peas, tomatoes, turmeric, garlic and chickpeas.

Zoe has never again had a reaction as serious as the one she had as a baby because her parents have tried hard to keep her out of harm's way. They say that it's like walking a tightrope.

This act was made tougher when Ms Huang and her husband moved to Singapore in 2004, where they found that there was not much awareness about the life-threatening nature of food allergies.

For Ms Huang, this was a nerve-racking time.

'I remember people would want to give her something to eat and they'd say, 'Aiyah, let her try just a little'. They didn't know that just a drop would be enough to send Zoe into shock,' she said.

Realising that there were other mothers like herself, adrift and without a paddle in the food allergy world, she decided to form a support group through which they could share information and tips on cooking and managing emergencies.

The Food Allergy Network, as it is known, has grown to become an outlet for the stress experienced by parents of kids with serious food allergies.

'You are constantly worrying that your child may eat the wrong thing at school or with friends and not get help in time,' Ms Huang said.

Food allergies in Singapore

The study of food allergies in Singapore children is still an emerging field, according to specialists in this area. They say that allergies in Asian children seem to be different, in some ways, from those commonly seen in the west.

For instance, the life-threatening reaction to peanuts and tree nuts, commonly seen in the United States and Britain, are negligible here.

While peanut allergies do occur, the symptoms produced are less severe and do not require emergency treatment. In fact, Dr Lee estimates that nut allergies are 10 times less common here than in the US.

According to local studies, food allergies are on the increase among children here, with at least 4 to 5 per cent of children suffering from them.

A study by the Department of Paediatrics at the National University of Singapore showed that bird's nest is the most common cause of anaphylaxis in children here, followed by crustacean seafood, egg and cow's milk.

Reactions to egg and milk occur mainly in infants while the remaining reactions occur in older children, with the oldest reacting to crustacean seafood.

What's inside this emergency kit - not much taller than a can of soda - which is a must for parents of children with serious food allergies?

Though a person can develop a food allergy at any point in life, it is frequently seen in childhood.

'Of all the age groups, young children are most prone to food allergy,' said Dr Lee. 'It can occur as early as the first month of life, but it is often seen in the first two years of life when new foods are introduced.'

Causes and treatment options

Dr Lee explained that a food allergy is due to an abnormal immune response to food proteins. In normal people, these proteins are well tolerated.

'In those who are allergic, this tolerance breaks down and results in an antibody response to the food protein,' she said.

But children can outgrow some of their food allergies.

'They can outgrow cow's milk and hen's egg allergies,' said Dr Lee. 'Up to 80 to 90 per cent will outgrow it by the age of five.' However peanuts and tree nuts tend to produce long-lasting allergies.

There is no cure for food allergies at present but there is ongoing research for various treatments, including oral immunotherapy and fusion proteins.

There are also a number of alternative treatments. But Ms Huang is sceptical.

'Parents can sometimes get desperate and try anything. But it may not be safe or effective,' she said.

Parents of kids who are allergic to foods quickly learn that prevention is the best cure. So they transform their homes into safe havens, avoiding the allergy-inducing foods and devising new recipes.

Some, like Ms Huang, take the added precaution of packing an emergency kit containing an epinephrine injection, just in case their child unwittingly ingests an allergy-causing food.

For Ms Huang, her daughter's allergy has also meant a different lifestyle, buying mostly organic produce and avoiding processed food.

There are plenty of things that Zoe, an active little girl who also loves to read, can eat. She likes sushi, steak, french fries, broccoli, cabbage, salads and apple cider vinegar. She said she knows what she is allergic to and how to say 'no' when offered such food.

'I just say 'no, thank you, I have a food allergy',' she said.

That doesn't stop her mother from worrying, though.

'It's really quite a roller-coaster ride,' said Ms Huang.