ONE minute you are in the pink of health enjoying your meal and, the next, you could be doubled over in pain, utterly confused.

If you have a family history of allergy to certain food, it may be wise to take note of what these are.

Food allergies can strike without warning.

If you do have a food allergy, always be meticulous in asking what's in your food.

The product you are allergic to could be in the sauce, soup or even drink.

While on the ground, an allergy patient can be whisked away quickly for medical treatment at a hospital.

The scenario is different when you're kilometres away from a hospital, having a severe allergic attack on a boat or in a plane.

"For medical emergencies, the process of travel does not make a difference to the severity of the attack. The only issue is that a patient may be away from early medical help in a hospital and that is dangerous," says Dr Kuljit Singh, an ear, nose and throat consultant with Prince Court Medical Centre.

"If you have a known allergy and plan to travel, get your physician to write a letter explaining what it is and any possible medications you may need or be allergic to. It will be a great help to people attending to you should there be emergency."

Dr Kuljit encountered a medical emergency involving a food allergy in 2004 when flying from Kuala Lumpur to Istanbul.

A passenger had a severe allergic reaction after eating his meal.

"He was a Turkish man who spoke very little English so it was difficult to understand what he was saying. He was screaming in pain. The left side of his face, including his ear, had turned completely red and he was clutching his ear in pain.

"I was travelling with a colleague at that time and a stewardess approached us for help. It was meal service at that time so we suspected an allergy. The stewardess fetched the physician's kit on board (which can only be opened and used by a certified medical practitioner, doctor, paramedic or nurse).

"Using a syringe from the kit, I gave the patient an anti-allergy shot, then told him to lie down. He dozed off immediately, and slept for two to three hours, waking up just as we landed. Later when we reached Istanbul, he was hale and hearty, and came up to thank us."

All commercial planes have a physician's kit which contains anti-allergy medication in addition to IV infusion set, syringes, valium, among other things.

Most carry epi-pens in the event of an emergency.

An epi-pen is a drug releasing device which controls acute allergy reactions but does not cure the allergy.

It is designed for immediate use in an emergency, to treat an allergic reaction fast and give a patient time to get to a hospital or medical centre.

Another doctor who treated a sudden food allergy while on board a flight was Datuk Dr Jeyaindran Tan Sri Dr Sinnadurai, senior consultant pulmonary and critical care physician and head of department of medicine at Hospital Kuala Lumpur.

"It was a minor allergy. The passenger got a rash and mild swelling of the lips and face. There was no bronchospasm nor was there any stridor. We were not sure about the cause, but suspected it might have been the food. I treated him with oral anti-histamines from my own supply. I carry my own little bag of 'tricks', including my stethoscope, when I travel!"

Asthmatics have to be wary when travelling because of allergens.

"They must always be ready to face the possibility of a worsening of the asthma due to environmental allergens or weather conditions.

If that occurs they should know how to increase the dose of their preventers (inhaled steroids)."

Common triggers

WHAT are the common causes of allergies? Prince Court Medical Centre ear, nose and throat consultant Dr Kuljit Singh answers questions:

What causes an allergy?

It is caused by a protein material from the environment, food or anything that directly comes in contact with us.

What are the most common allergens - indoors and outdoors? Are these preventable and how can we remove allergens from our home and control our exposure to allergens in the environment?

Common allergens are house dust mites, fungi, cat saliva and fur, dog fur, seafood and dairy products. These are difficult to prevent 100 per cent, as it would require total avoidance.

What happens during a severe allergic reaction and how is it reversed?

There is an increase of chemicals within the body like histamines, for example, which causes body organs to react badly. This can include respiratory distress, skin reactions and total collapse of body systems. In most cases early medical treatment can reverse the attacks .

Can an allergy in childhood disappear in adulthood?

Common childhood allergies wean off in view of altered immunity sensitivity.

Can an adult develop an allergy suddenly in later years?

Yes, it is possible but sometimes there could be a cross allergy to something else with similar proteins. It is hard to predict. We're not sure why it happens but our immunity gets seasoned and waits for triggering factors.

In what circumstances can you die of an allergy?

The worst case scenario is when allergy causes a total shut down or obstruction of the airway due to inflammation and release of secretions which causes total cessation of breathing followed by cardiac arrest.