Medical information

Is there a medical cure for food allergy or intolerance?

As yet there is no actual cure or ‘magic bullet’ for a food allergy or intolerance. That said, a considerable volume of research has been conducted into the nature and causes of the allergic or intolerant condition allowing us a greater understanding of the conditions and underpinning hopes for a medical cure in the future. For the moment, management of the condition is based on strict avoidance of the causative foods. In the case of food allergy, treatment usually involves antihistamines for a mild reaction and adrenaline for a severe reaction.

How is a food allergy diagnosed?

  1. A physical check-up will rule out other more obvious medical problems in the fist instance.
  2. A concise dietary history including a description of the symptoms and the foods suspected of triggering these symptoms.
  3. A history of atopic disease in the family including any allergies to foods or other materials, any food intolerances including coeliac disease and incidences of asthma, hay fever, eczema, etc.
  4. The patient may be instructed to keep a food diary of their eating habits, symptoms and medications to help pinpoint the problem.
  5. An elimination diet may be used to link the symptoms with the food or foods causing them. This may not be advisable if the reaction has been severe.

If a food allergy is suspect after these investigations, more diagnostic methods are employed:

  1. Skin prick tests are used to determine the reaction to a range of foods or to see if the problem could have been caused by other common allergens such as dust, cat hair or pollen. It can also give an indication of how strong the reaction is.
  2. Blood tests are used to determine the strength of the immune system response to an allergen. This usually involves a radioallergosorbent or ‘RAST’ test in which the level of IgE antibodies – the kind specifically associated with a food allergic reaction – are measured.
  3. Allergen provocation tests are generally regarded as being diagnostically the most definitive. The ‘double-blind placebo controlled food challenge’ (DBPCFC) is used to administer the suspect allergenic food to the patient orally under clinical supervision. The DBPCFC can be risky for people who may have a severe food allergy and in this case is only carried out in a hospital setting with full resuscitation equipment.

What is oral allergy syndrome?

In some cases allergic reactions can be confined to the mouth, lips, tongue or throat area. Here, the symptoms which are generally tingling and localised swelling usually occur within one hour of eating the offending food. Oral allergy syndrome is normally linked to the consumption of fresh fruit and vegetables. Patients often complain that something is stuck in their throat but progression to a severe reaction is unlikely. People with oral allergy syndrome caused by fruit and vegetables often have an associated allergy to certain pollens and may get hay fever when these pollens are in season.

What about exercise induced food allergy?

This is a rare condition where someone can have a severe allergic reaction within a couple of hours of eating a particular food, if they take vigorous exercise. People who are sensitive in this way may normally be able to eat the food with only a mild reaction or no reaction at all.

How is a food intolerance, including Coeliac condition, diagnosed?

If you suspect you have a food intolerance or coeliac disease your doctor will do a physical check-up to rule out other medical problems. Your dietary history will also be investigated, including a description of your symptoms and the foods you suspect of triggering these symptoms. The doctor will also ask about your family, as a family history of intolerances or coeliac condition is known to be a significant risk factor. The diagnosis of coeliac condition is based on a blood test for certain antibodies. The outcome of this test may require a further investigation in the form of a small bowel biopsy in which a small sample of the lining of the small bowel, which is damaged in coeliac condition, is removed for analysis. 

Clinical diagnosis of lactose intolerance is based on measuring blood sugar level, the acidity of the stool (infants) or the presence of hydrogen in the breath, all being affected by the consumption and metabolism of lactose in the body. 

What is anaphylaxis?

If enough IgE antibodies are released during an allergic reaction, the person may experience anaphylaxis, or anaphylactic shock which is really a combination of both mild and severe symptoms. Mild symptoms include itching or swelling in the mouth and throat, hives, runny nose and eyes, reddening of the skin, nausea, diarrhoea and/or vomiting. The severe symptoms are swelling of the airways leading to suffocation and a dramatic drop in blood pressure (shock) leading to fainting, collapse or a loss of consciousness.

Both symptoms are life-threatening. A person who takes an anaphylactic reaction may experience one or both of these severe symptoms in combination with any number of milder symptoms. An anaphylactic reaction is usually rapid and can be fatal within minutes. However, sometimes, for reasons as yet unknown, there is a delay of a few minutes to several hours before the person takes an anaphylactic reaction. 

What is adrenaline for?

The effects of an anaphylactic reaction must be counteracted immediately by administration of adrenaline (epinephrine). This is delivered in a specific dose from an autoinjector and anyone who is susceptible to anaphylactic shock must carry one on their person at all times. These are not over-the-counter medications and must be prescribed by a doctor. The autoinjector is designed to deliver a specific dose of adrenaline to counteract the effects of an anaphylactic reaction.

However, it is extremely important that the allergic person, their guardians and friends are aware of the autoinjector and how and where to administer it in the event of the person becoming so ill during a reaction they are unable to use it themselves. Autoinjectors are marketed in Northern Ireland / UK as EpiPen® and in the Republic of Ireland as Anapen®.

What is the procedure for dealing with a severe allergic reaction?

If someone takes a sufficiently severe reaction that an autoinjector has to be used or indeed takes an anaphylactic reaction without an autoinjector being available, medical help should be sought immediately by dialing 999 and asking for the ambulance service. It is important to explain that you think the customer may be having a serious allergic reaction. Hospital treatment and overnight observation are recommended where someone has taken a severe reaction.

What can staff do if they think a customer may be having an allergic reaction?

If someone is experiencing difficulty breathing, if their lips or mouth are swollen, or if they have lost consciousness, you should immediately:

  1. Call an ambulance (DIAL 999) and describe what is happening
  2. Explain that you think the person may be having a serious allergic reaction
  3. Do not move the person because this could make them worse
  4. Stay with the customer until help arrives
  5. Send someone outside to wait for the ambulance

Can you get anaphylaxis if you have a food intolerance or coeliac condition?

Anaphylaxis or anaphylactic shock has not been associated with food intolerances such as lactose intolerance or with coeliac condition. This is because the antibody responsible for triggering allergic reactions including anaphylaxis, IgE, is not involved in food intolerance or coeliac condition.

If I am concerned that I have a food allergy, where can I go for help?

If you have had symptoms after you ate or were exposed to something, be it a food or any other material, and if you think these symptoms could have been due to an allergic reaction, then you should visit your GP. You may then be referred onto an allergy specialist. A list of such specialists who operate in the Republic of Ireland is available on the website of the Irish Anaphylaxis Campaign. Further information about specialists in Northern Ireland is available at Allergy NI.

Your GP may also refer you to a dietician or nutritionist who will then advise you on the proper avoidance diet to adhere to including alternative sources of nutrients. Alternatively you are entitled to make an appointment directly with a dietician without going through your GP. 

  • In the Republic of Ireland a list of dieticians who specialise in food allergy and intolerance is available on the website of the Irish Nutrition & Dietetic Institute (INDI). A private allergy clinic – the Allergy Diagnostic and Therapeutic Centre – operates out of St. James’s Hospital, Dublin. 
  • A list of dieticians operating in Northern Ireland can be obtained from Freelance Dietitians, which is a database of registered dieticians who are affiliated to the British Dietetic Association.