Food Allergy: A Global Problem
Before going to the specific subject of ‘food allergy’ one should know what an allergic reaction is. Immune system of our body gives us protection from various illnesses. Abnormal reaction of immune system to any external object is allergy. Object responsible for allergic reaction is called ‘allergen’. Example of allergen may be dust, pollen, cement, paint, gas, fungus, plants, medicines, food item, blood for transfusion etc. During the process of allergic reaction a protein named ‘immunoglobulin’ is released by the immune system. This immunoglobulin is named as antibody. There are five various types of antibody viz. IgA, IgD, IgE, IgG and IgM. http://www.webmd.com/a-to-z-guides/immunoglobulins. A chemical substance (neurotransmitter) known as histamine is released during antigen and antibody reaction. Depending upon the site where histamine is released symptoms and sign develop. Allergic reaction may be mild, moderate or severe. Severe and life-threatening allergic reaction is called ‘anaphylactic reaction’.
Food allergy is a global problem and there is no cure except prevention of food allergy. Various sources indicate in India 25% population suffer from some kind of food allergy where as 40% of western population suffer from food allergy.
http://www.foodsmatter.com/allergy_intolerance/miscellaneous/articles/food_allergy_india.html Worldwide 4 to 8 percent population suffers from food allergy. Compared to adult cases of food allergy is more on the age group under 18 years. But person of any age may get food allergy. County wise food allergen may be different. As example in Gerrece, Spain and Italy apple, peach and melon are common allergen, In Bangladash jackfruit, in Ghana pineapple, buckwheat in Japan, royal jelly in Hong Kong. In India food allergens may be milk and dairy products, peanuts, vegetables & fruits (cucumber, bringal, ladies finger, papaya, potato, sesum,pineapple, jackfruit, watermelon). In India every year nearly 100 to 200 persons die of food allergy. About 3 million Indians suffer food allergy due to peanut, http://www.foodsmatter.com/allergy_intolerance/miscellaneous/articles/food_allergy_india.html
Researchers have detected at least 160 varieties of food allergens. Extensive research work is going on in various countries like USA, Australia, Japan, Ghana, Singapore, Philippines. Ninety percent food allergies are produced by the following 8 food substances, Viz. Milk, egg, peanut, fish, shellfish, tree nuts, wheat and soya bin. https://www.foodallergy.org/allergens
Milk allergy is due to a protein called Casein. It is the most common food allergy in infants and young children. Person having food allergy cannot take dairy products like cream, paneer, butter, ghee, curd, lassi etc. There is possibility that these people may have other allergy problem like allergic rhinitis, eczema, asthma.
Allergy to egg –
Egg allergy : some people get allergy to egg yolk, some have allergy to egg albumen and some have allergy to both the components, Some have allergy to duck egg, but no allergy with chicken’s egg. Some vaccines ( Measles Mumps Rubella (MMR) and Flu vaccine are prepared from egg protein. According to Amarican academy of Pediatrics these vaccines may be administered to patients having egg allergy. . http://www.foodallergy.org/allergens/egg-allergy
In some children egg allergy disappears with growth, but in some it remains lifelong.
Peanut allergy -generally remains lifelong. They may get even anaphylaxis. Person having peanut allergy cannot take sweet or salted items prepared from besan (powder of peanut).
Fish allergy – Tuna, Salmon, Prawn or any sea fish can cause moderate to severe allergic reaction.
Person having nut allergy cannot take cashew, walnut or any other such item.
Person having wheat allergy cannot take Ata, Moida, Cornflask etc.
Person allergic to Soya bean should avoid all kind of soya products.
Preservatives, coloring agents, food additives like monosodium gluconate can cause food allergy of different degrees in some persons.
Symptoms and signs of food allergy: –
Development of hives (skin patches having redness & itching)
Angioedema – swelling of eye, lip & tongue.
Headache, giddiness, fainting, running nose, hoarseness of voice, difficulty of swallowing.
Gastrointestinal symptoms – nausea, vomiting, abdominal cramp, diarrhea.
Food Protein Induced-delayed Entero-colities Syndrome (FPIES) –
FPIES is a condition seen in some infants and young children when mother’s milk is substituted or changed to cow’s milk other food items and the child develops severe food allergy with symptoms of blood-mixed stool, abdominal cramp, vomiting & dehydration. Emergency fluid replacement is a must in the treatment to save the life of the patient.
Oral allergy syndrome –
Oral allergy syndrome is a condition where food allergy produced by fruits & vegetables is seen limited to oral cavity
Genetic link – since food allergy is seen among more than one family member food allergy may have some genetic link.
Generally food allergy can be diagnosed from the history. Sometimes skin test or blood test is performed to identify an allergen. Ig E antibody is present in abundant quantity in patients having food allergy.
Avoidance is the best policy.
Caution in taking food outside home particularly in a restaurant is essential as a special measure.
Anti histaminic injection, oral medicine, steroids like dexamethasone, methyl prednisolone, adrenaline may be needed in some cases of food allergy to get rid of allergic manifestations. In some developed countries patients carry penfill adrenaline injections.
It is noticed that breast-feeding to a longer duration gives protection to the child from food allergy and other allergic conditions like allergic dermatitis and bronchial asthma.