What is food allergy?
Two different conditions
Although most people describe any illness which they think maybe caused by food as a food allergy, they may only be partially correct.There are in fact two different conditions which link food and 'allergic reactions'. One is food allergy: a condition which is rarely curable in which specific foods cause an immediate and often dramatic physical reaction - vomiting, diarrhoea, cramps, wheezing, swelling of the airways, a severe drop in blood pressure etc.
The other is food intolerance or sensitivity. This is often linked to other health problems and its symptoms are far less defined. However, food sensitivities will often improve or disappear completely over a period of time.
In food allergy, a food (usually peanuts, tree nuts, milk, egg or shellfish although it could be anything) sets off what is known as an IgE mediated reaction in the body. In layman's terms, some element in the food (usually a protein) sets of a chemical reaction (creates an IgE antibody) within the cells of the body. These antibodies release chemicals, such as histamine, which, in turn, cause the 'allergic reaction' - hives, swelling, breathing difficulty etc.
The reaction can occur within minutes and rarely takes more than a few hours. It is usually quite severe and, in cases of anaphylactic shock, can be fatal.
There is as yet no known cure for true food allergy although desensitisation techniques have been found to be successful in some cases (link). As of now the only treatment therefore is total avoidance of the relevant food and, if the reactions are very severe, carrying an 'antidote' to the particular allergen.
Anaphylactic Reaction
A very severe or anaphylactic reaction can cause the airways (throat, mouth and nose) to swell so dramatically as to prevent breathing. It can also cause severe wheezing or a fatal drop in blood pressure. An immediate injection of adrenaline will usually arrest these symptoms although the person will need emergency hospital treatment.A portable adrenaline shot (an Epi or Ana-pen link ?) is now available which can be administered by anyone and which a person with a serious allergy should always keep with them.
If anyone suspects that they have a serious allergy to any food (or chemical or insect bite) they should attend a specialist allergy clinic and always carry the appropriate medication.
Food sensivity or intollerance
A food sensitivity or intolerance occurs when the body has difficulty in digesting a particular food and therefore reacts against it. In medical terms the body's reaction to that food is to create not IgE but IgG antibodies. These do not spark off 'allergic' chemical reactions as do IgE antibodies which is why there may be no immediate physical reaction to the offending food.In normal digestion the foods we eat are broken down (through chewing and the action of the acids etc. in our stomach and our intestines) into their component parts. The useful ones (the nutrients) are absorbed into the blood stream through the digestive tract (or 'gut wall') to nourish the body, the redundant ones are flushed out through the bowel.
However, if the foods are not properly broken down through some digestive malfunction the body will either not be able to absorb them properly or, since they have not been properly 'processed', may react against them. In the case of lactose intolerance, for example, the body fails to manufacture read more
