Food Allergy


Find Allergy Clinics »

Food allergies affect approximately 3% of the population. An allergic response occurs not upon the initial ingestion of a food substance, but upon subsequent exposure. Many people find that the first time they try something there is no reaction at all. It is only when they go to eat a particular food again that the response occurs. This is what is known as a hypersensitivity reaction. The reaction occurs due to a sensitisation of the immune system to whatever it is in a food substance that the body identifies as an allergen. These are usually proteins that can survive the various obstacles in place to cross over the gastrointestinal membrane and enter into the circulatory system. This initial exposure causes a release of IgE from white blood cells called lymphocytes. The IgE then circulates throughout the body and attaches itself to various different cells and organs. The next time the particular allergen is ingested, once in the body, it is drawn to the previously released IgE molecules that attached to specialised cells located throughout the body in various tissues and various and organs. The specialised cells, called mast cells, are then stimulated to release a host of chemicals and hormones (i.e. histamine) into the bloodstream and cause the ensuing allergic response symptoms.

For most individuals, food allergies are more likely to occur if there is a family history of allergy susceptibility. The allergy does not have to be to food in particular, but can be any of a range of different types of allergies such as hay fever or animal dander.

It is vitally important for individuals who suffer from a food allergy to identify it and avoid it. While some allergic responses can be mild and limited to nausea and vomiting, more severe reactions can lead to anaphylaxis and even death. For those who suffer from a life threatening food allergy (more often seen with nuts and shellfish) it is important to carry an emergency dose of adrenaline in case the offending food is accidentally ingested. This is given in the form of an injection and acts as a form of antidote to the food allergen and prevents the heart from stopping.

Food Allergies to Dairy Products, Gluten, Eggs, Fish, Shellfish, Nuts, Soya & Additives

Most often allergic reactions are due to exposure to food stuffs such as dairy products, gluten, eggs, fish and shellfish, nuts, soya, and a variety of different additives. Food allergies can sometimes be mistaken for food intolerance, which is slightly different to a true allergy.

Food intolerances

What you might think is an allergy may just be an intolerance to a certain food or foods. While a food intolerance can still be uncomfortable, your symptoms may disappear if you reduce your consumption of the offending food. Either way, it can be beneficial to have a consultation with an allergist to discover any food allergies, or even minor food intolerances, which may have been causing slight symptoms, such as headaches or bloating. By reducing your intake of the foods provoking the latter, you may be able to improve your general health and wellbeing with little effort.

Food allergies

If there is someone in your family who has been diagnosed with a food allergy then it is more likely that you may have or develop one too. The predisposition to produce the antibody IgE that reacts, or rather overreacts, to certain allergens like food seems to be a hereditary trait. This only occurs once the individual has been exposed to the food. After this, the next time you consume the same food, the body produces antibodies specifically targeted at this allergen, thus causing a reaction. It is important to note however that a food allergy can develop at any time in your life, not just the second time you consume a particular food. It is therefore crucial not to dismiss a type of food as a possible cause or factor in your reaction merely because it has not provoked a reaction previously.

Allergies to nuts

This can be one of the most frustrating, and dangerous, allergies to have. Some people are not allergic to nuts but experience some discomfort (such as a tingling of the mouth and lips) after consuming a certain amount. This is an intolerance to nuts rather than an actually allergy. Although rare, those with nut allergies can suffer the potentially fatal reaction of anaphylaxis. Though always advisable, if you have a severe nut allergy it is a good idea to talk to your doctor or allergist. It may be necessary to avoid all foods that have not been prepared in a completely nut-free environment. Some people are so allergic to nuts that they cannot even travel on planes which serve nuts because the particles that circulate can get into the respiratory system and even this can provoke a life-threatening allergic reaction. It is therefore important that you are aware of just how severe your allergy is and seek medical advice so that you are fully informed of your condition.


« Pregnancy, Breast Feeding & Hay Fever Gluten Allergy »





Guide to Food Allergies