A food challenge may be recommended to some patients under some circumstances. These circumstances might include:
- Determining if a person has outgrown an existing food allergy
- To clarify a suspected food allergy if history or allergy tests are not conclusive
- When a tests demonstrates a positive outcome even though the person has never had an allergic response to the food.
The procedure is time consuming and involves small amounts of the particular food being given to the person while under medical supervision to determine if the food being tested causes an allergic reaction.
The process can take up to 4 hours though if a reaction occurs the challenge is terminated and treatment for the allergic reaction is provided. If the challenge does lead to a reaction, this is called a positive result and the patient will be considered to be allergic to that food. If the challenge does not cause an allergic reaction the test will be ‘negative’ and the patient will be asked to include the food in their diet.
Food challenges are carried out on people who have suspected allergies. They should therefore be carried out with a properly qualified allergy specialist who is able to treat an allergic reaction should one occur.