A food challenge entails giving initially tiny, then increasing amounts of food to the person in a controlled setting. We bring the child in to hospital or clinic for the day and give them small amounts of the food to which they had a positive allergy test or previously been allergic to, to see if there is any reaction. This is done in a very controlled way and the doctors and nurses will be there with you and your child to watch them closely. That way we can notice reactions early and treat them if needed.
If the child has no reactions to a very tiny amount of the food, then we will give them a little more, step by step, until we reach the top dose. The top dose will be similar to a normal “portion” of the food, for example one cupful of milk. In between each dose we will gently examine the child to look for any reactions, and also measure the temperature, pulse rate, heart rate, blood pressure and oxygen levels.
If the person eats the top dose without a reaction, the challenge has been passed and the person can eat the food regularly from now on. (Strangely this is called a “negative” challenge). The nurse will also phone you at home after 2 days to make sure everything is alright and to ask if the child’s eczema has got any worse.
If there are any reactions along the way, we will stop the food challenge and treat the child if necessary. This is failing the challenge; the person is allergic and should continue to avoid the food. (This is called a “positive” challenge).