Allergy is the state of hypersensitivity of the body to certain substances known as allergens. These may be substances present in the atmosphere, which one may inhale or apply locally on the body or ingest in the form of food or drinks. Of all these allergies, allergy to food substances is the most troublesome. Somebody having allergy to a food substance may not be aware of it. He or she may be consuming that item everyday and getting sick. He may not be aware of the fact that a particular food item or one of its ingredients is making him sick. The body becomes sensitive to a particular substance in the food and reacts by producing antibodies. Thus on subsequent exposure to the food substance, an antigen, antibody reaction is triggered, manifesting in various ways. Food allergy manifests in the form of skin rashes, itching, dry cough, sneezing or running of nose, breathlessness, swelling of eyes and throat. A person may have one of these or many of these complaints together after exposure to the particular allergen (allergy producing substance). Diarrhoea, nausea and vomiting may also occur in some persons due to food allergy. This sort of manifestation of allergy is more common in infants and young children due to allergy to milk protein. Food allergy is also different from the sickness caused due to food poisoning as the underlying cause is different. These symptoms may be present chronically if someone is consuming the allergy producing substance daily or it may occur acutely if it is a one time exposure. At times the allergic manifestation may be severe and fatal. One may have allergy to the natural ingredients in a consumable item, like proteins present in eggs, soy products, milk and milk products or nuts. There may be allergy to the spices used in cooking a particular dish. One may have allergy to chemicals present in foods. This is in fact one of the most common cause of food allergies occurring in the developed western countries. These chemicals are used for preserving the food or enhancing the flavour or colour or as emulsifiers. This sort of allergy develops mostly with preserved foods or instant ready to eat foods. One needs to be aware of food allergies to be able to link an acute illness to a food item. Otherwise he or she may spend their time and money in visiting doctors and undergoing various tests to find the cause for the underlying illness. The picture gets more confusing if somebody has diarrhoea or vomiting as one mostly suspects food poisoning in such cases. A high degree of suspicion is needed with tests to establish diagnosis of food allergy. Diagnosis becomes easy if there is a history of allergy in the family among blood relatives. High level of eosinophils, (a type of white blood cell indicating allergy in the blood is suggestive of allergy. Another type of test used for diagnosing food is the intradermal skin test. Potential allergens (allergy producing substances) are injected subcutaneously) and the reaction produced (in form of a flare or wheal over the skin) is read after 48 hours. But this test can be done only when one has no problem for minimum 2 days; otherwise there is a risk of producing a severe fatal allergic reaction. Food challenge is useful for diagnosing food allergy and also in identifying the food items which produce the allergy. One should try to omit one food item from the daily diet turn by turn for 2 to 3 days and then include them one by one. In this way it will be possible to pin point the allergy producing substance. Because any food substance to which one has allergy, when consumed, will produce illness in that person. On avoiding that substance, the person will remain healthy. Ideally one should take freshly cooked or raw natural fresh food. Processed or ready to eat fast foods should be avoided. Infants having allergy to milk are given whey or formula feeds. Anti allergy drugs like chlorphenaramine maleate, promethazine, cetrizine, e.t.c. are used to relieve symptoms of food allergy. But they tend to cause drowsiness, hence interfere with one’s work. That’s why it is better to possibly identify and avoid food allergy. rachna212002@yahoo.co.uk
