Food Allergen Challenges Frequently Asked Questions (FAQs)

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Q 1: What is a supervised food allergen challenge?

Food allergen challenges are procedures where small and increasing amounts of a food (as set out in standard protocols) are fed to a patient in a medical clinic. The patient is monitored to confirm if the food being tested causes an allergic reaction.

Challenges are supervised by a clinical immunology/allergy specialists or trained and experienced paediatricians.

Most challenges take two to three hours to eat the required doses of food, followed by two hours of observation.

Q 2: What happens if there is no allergic reaction resulting from a food allergen challenge?

If the challenge is completed without an allergic reaction it is called ‘negative’, which means that the patient:

This can have a major positive impact for patients and their families, as they no longer need to avoid a food that may be a major part of their usual diet.

Q 3: What happen if there is an allergic reaction resulting from a food allergen challenge?

If an allergic reaction occurs, the challenge is usually called “positive”, and the challenge is stopped:

The severity of the allergic reaction during the challenge does not predict the severity of future allergic reactions. For example, if a person has a mild allergic reaction during the challenge, a reaction at another time  could be more severe or life threatening (anaphylaxis).

Q 4: Who can perform supervised food allergen challenges?

Food allergen challenges should only be performed in carefully selected patients by a clinical immunology/allergy specialist or a trained and experienced paediatrician. For patients who are at risk of a severe allergic reaction (anaphylaxis), food allergen challenges must be performed by trained and experienced staff, with immediate access to emergency treatment for anaphylaxis.

Q 5: Why are supervised food allergen challenges performed?

Food allergen challenges are used to confirm:

Q 6: Why are supervised food allergen challenges sometimes performed after other allergy tests?

A positive food allergy test using skin tests or blood tests for allergen specific immunoglobulin E (IgE) antibodies, means that a person's immune system has produced an antibody response to that food. This is known as sensitisation.

It is possible to have sensitisation without allergy, which means that the person can eat the food without any symptoms. For this reason, it can be important to confirm a positive allergy test with a food allergen challenge.

Q 7: How do you prepare for a supervised food allergen challenge?

If your child is having a supervised food allergen challenge:

Q 8: How are allergic reactions resulting from supervised food allergen challenges treated ?

Food allergen challenges are performed in a controlled medical environment with medical and nursing staff experienced in treating anaphylaxis. Therefore, the way an allergic reaction is treated in a hospital may vary slightly from the instructions on the ASCIA Action Plan for Anaphylaxis. This is because hospital staff have ready access to blood pressure and oxygen checks, oxygen masks and other equipment.

It is important to follow instructions on the ASCIA Action Plan for Anaphylaxis when not in a hospital setting.

 

© ASCIA 2019

ASCIA is the peak professional body of clinical immunology/allergy specialists in Australia and New Zealand.

ASCIA resources are based on published literature and expert review, however, they are not intended to replace medical advice. The content of ASCIA resources is not influenced by any commercial organisations.

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Updated May 2019