THE word "allergy" is coined from two Greek words meaning altered reactivity.

A food allergy occurs when the immune system responds defensively to a specific food protein that is not harmful to the body.

A severe food allergic reaction known as anaphylaxis usually occurs within minutes of eating the offending food and symptoms.

It may include a tingling sensation of the mouth, swelling of the tongue and throat, hives (urticaria), skin rashes, vomiting, rhinitis, abdominal cramps, difficulty in breathing (asthma), diarrhoea, a drop in blood pressure, or even a loss of consciousness.

Fish, milk, shellfish, nuts, wheat and eggs are the most common foods that cause allergies. Food intolerance, on the other hand, may or may not involve the immune system and may occur from additives or chemicals that are in the food.

In Malaysia, more than 100 species of fish are sold in the local market.

In countries where consumption of fish is high, allergic reactions to fish are common, predominantly in patients with food allergy.

However, not much is known of the prevalence of fish allergy in the local population.

It seems that the frequency of fish allergy varies according to geography and exposure.

In a study done by the Institute of Medical Research (IMR, 2002), about 562 atopic patients were skin prick-tested (SPT) with a few different types of fish extract.

It was shown that 126 people of the atopic population were skin test positive to fish. The prevalence skin test reactivity to kembung was the highest at 9.3 per cent while the lowest was ikan pari at 2.8 per cent.

Fish muscle fiber is almost identical to the counterpart in red meat. Fish has lower collagen content than meat, making it softer.

Many techniques used for processing meat are applied to fish, producing such products as fish burgers, sticks, sausages and nuggets. This process adds new allergens which may be responsible for food allergic reactions.

Most allergies are inherited, which means they are passed on to children by their parents.

While many children may outgrow allergy to cow's milk, they may continue to be hypersensitive to fish and shellfish in later life.

Allergies cannot be cured but the symptoms they cause can be treated and controlled. This may require making changes in the environment or behavior to avoid or reduce exposure to certain allergens.

Even with treatment, the body's immune system will continue to react when exposed to allergens.

If you suffer from a fish allergy, avoiding fish and food containing fish products such as Caesar salad, roe (fish eggs), imitation seafood (as is often used in sushi) is the only way to prevent a reaction.

Blood tests can be done to eliminate possible culprits and it may be worthwhile considering one done to avoid anaphylactic shock.

Extremely sensitive patients have suffered anaphylactic shock after eating foods cooked in reused cooking oil, or when utensils and containers have been used earlier for cooking fish.

Researchers found that the consumption of omega-3 fatty acids in the form of fish oil concentrates may be an alternative source of supplying these vital fatty acids for those with fish allergy.

This is due to the fact that the protein which coats the allergens in the fish is filtered out during the manufacturing process of fish oil.

The quality of the fish oil you choose is very important. High-quality oil should be independently lab-tested and has to be free of mercury and other environmental toxins.

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