Food Allergies

Food allergy is defined as “an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food”. Food allergies refers to an immunological reaction to a food or part of a food. If a non-allergenic mechanism is involved the response is a food idiosyncrasy. The term food intolerance includes any adverse reaction to food along with allergenic and non-allergenic reactions.

Allergen

An allergen is any substance (antigen), most often eaten or inhaled, that is recognized by the immune system and causes an allergic reaction.

Prevalence of food allergies

It has been reported that 6% of children and 3% of adults have food allergies, with research work suggesting increased prevalence worldwide over the past few decades. Allergy can be inherited. Food allergies are very difficult to diagnose. Food allergy is a public health concern due to its increasing prevalence and it’s a life-threatening possibility.

The symptoms of food allergy are:

Systemic: Anaphylaxis which is allergic shock reaction

Gastro-intestinal: Vomiting, abdominal pain, diarrhoea, malabsorption, enteropathies

Respiratory: Rhinitis, sinusitis, cough, wheezing, pulmonary infiltration

Cutaneous: Rash, utricaria, eczema

Manifestation of food allergies in childhood

Appearance of an allergic reaction can occur at any time during infancy and childhood. Infants are more susceptible to allergies probably because their immune system is still not developed and also because of the permeability of their intestinal walls which allow allergens and immunoglobulins to pass through. But the allergies present in infancy usually do not persist in adulthood, most infants outgrow them.

All foods are potentially allergenic. Some foods are more likely to act as sensitizers because of the frequency of use and because they contain large amounts of allergenic substances.

During infancy the most common allergy is probably to cow milk. Milk allergy appears at a very early age and all the symptoms disappear spontaneously within two years.

Some of the other foods that are reported to cause allergies in infants are eggs, fish, some fruits, meats, nuts, chocolate and gluten containing cereals.

How to deal with food allergies in infants?

It is recommended that infants should be exclusively breast fed at least for six months especially if the infants have parents with allergies. This would minimize adverse reaction to foods. Then they should be introduced to foods one by one so that if any food is not tolerated it could be removed from the diet. And it should only be re-introduced under medical supervision.

Allergies to milk, egg, soy and wheat will resolve during childhood in most instances; allergies to peanuts, tree nuts and seafood tend to persist.

Treatment of food allergies in adults

Treatment of allergies is avoiding taking foods that contain the allergens. Those who are affected by allergy should be careful and should know about the hidden sources of allergen in the diet. Read food labels very carefully.

If severe allergies exist the allergen should be completely removed from the diet. And the food when re-introduced should be done gradually and under medical supervision. Management of food allergies typically involves avoiding allergen and emergency treatment in case allergen is ingested.

If a patient has severe allergy then utmost care should be taken while taking food to avoid that ingredient otherwise, it may become a life-threatening issue. The instructions of the doctor such as carrying medicine at all times etc should be taken very seriously.