The Australasian Society of Clinical Immunology and Allergy

Food allergy occurs in around 1 in 20 children and in about 1 in 100 adults. Fortunately, the majority of food allergies are not severe and usually improve with time, particularly in children. However, when a severe allergic reaction (anaphylaxis) occurs it can be frightening for patients and those involved in their care. People who suffer from food allergy therefore need to identify and avoid the cause, recognize the early symptoms of an allergic reaction and start treatment early.

How is food allergy managed?

People who are known to suffer from food allergy need to:

1. identify and avoid the cause (if possible)
2. recognize the early symptoms of an allergic reaction
3. know what to do if it happens again

Identifying the cause is the first step

Your doctor will normally ask a series of questions that may help to narrow down the list of likely causes such as foods or medicines consumed that day, or exposure to stinging insects. This approach will also help to exclude conditions that can sometimes be confused with food allergy. Skin prick or blood allergen specific IgE (RAST) allergy tests can help confirm or exclude potential triggers. You may be referred to a medical specialist (Allergist / Clinical Immunologist) for testing. 

Avoidance strategies are essential

If food allergy is confirmed, then it is important to:

• Carefully read the labels of foods in supermarkets for words indicating the presence of allergen. For example, the terms whey or casein indicate the presence of dairy products.
• Prepare for eating away from home as this poses greater risks. For example, it is wise to inform your host or restaurant chef about your allergy and the importance of avoiding contamination of your meal with allergen.

Care of food allergic children raises some particular issues

• Swapping of food needs to be discouraged.
• Children's parties may involve sending the allergic child with their own special party food.
• Those in childcare or at school might only be allowed to eat home prepared food and treats rather than communal food or that purchased at the school canteen. This has to be balanced with the difficulty involved in getting very young infants to eat only food supplied from home.
• Relatives, baby sitters and other caregivers need to be warned about the problem.
• Training of other care givers (such as school teachers) to use an adrenaline autoinjector for the emergency treatment of severe allergic reactions
• Support groups for families with members who suffer from anaphylaxis have been established, such as Anaphylaxis Australia www.allergyfacts.org.au and Allergy New Zealand www.allergy.org.nz

Not all food allergies are severe

Fortunately, the majority of food allergies are not dangerous. Mild symptoms include hives, sickness in the stomach or vomiting alone. Difficulty breathing due to throat swelling or asthma, or dizziness due to a drop in blood pressure, indicate a potentially life threatening severe allergic reaction (anaphylaxis).

It is important to recognize early symptoms of food allergy

Early symptoms of an allergic reaction often include an itchy mouth, face swelling and hives (urticaria), which can sometimes be followed by more severe symptoms. Patients with severe food allergies, however, should consider these as warning signals to get emergency medical help and to start treatment immediately until help arrives.

An emergency action plan should be developed for severe allergies

An ASCIA action plan for anaphylaxis is an essential part of management of severe food allergy. These are available on the ASCIA website www.allergy.org.au/content/view/10/3/ and should be completed by your doctor, who will advise you how to best manage your allergies.

The action plan includes instructions on how to use an adrenaline autoinjector, which works rapidly to reverse the effects of anaphylaxis.  This is considered to be essential first aid treatment for anaphylaxis.

Some patients will be advised to take other medicines like antihistamines. It is important to realize that these whilst this may help with mild symptoms it will not prevent a potentially life threatening, severe allergic reaction.

Other management issues for severe food allergy

• Patients who have had anaphylaxis may choose to wear a medical identification bracelet, which may increase the likelihood that adrenaline will be administered in an emergency.
• Some types of heart and blood pressure medicines (such as Beta-blockers or ACE inhibitors) can make severe allergic reactions worse, or interfere with the drugs used in treatment. These are best avoided.
• Immunotherapy (desensitization) is currently available for many inhaled allergens and stinging insects, but not yet for food allergens.

© ASCIA 2010

The Australasian Society of Clinical Immunology and Allergy (ASCIA) is the peak professional body of Clinical Immunologists and Allergists in Australia and New Zealand.

Website: www.allergy.org.au

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Postal address: PO Box 450 Balgowlah NSW Australia 2093             

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References

1. Sampson HA. Food Allergy. J Allergy Clin Immunol 1999; 103: 717-28 and 981-9

2. Sampson HA et al. Fatal and near fatal anaphylactic reactions to food in children and adolescents. New England Journal of Medicine 1992; 327: 380-384.

3. Vickers DW et al. Management of children with potential anaphylactic reactions in the community: a training package and proposal for good practice. Clin Exp Allergy 1997; 27: 898-903.

4. Committee Report from the Adverse Reactions to Food Committee of the American Academy of Allergy, Asthma and Immunology. Journal of Allergy and Clinical Immunology 1991; 87: 749-751.

5. Bernhisel-Broadbent J. Allergenic cross-reactivity of foods and characterization of food allergens and extracts. Ann Allergy Asthma Immunol 1995; 75: 295-303.

6. David TJ (ed). Food Allergy. J Royal Soc Med 1997; 90: 1-48.

Content last updated January 2010