An oral food challenge is a test performed in a medical facility under the supervision of an allergist to determine if an individual is allergic to a particular food. During the challenge, a patient eats an increasing amount of the food they might be allergic to, in timed intervals. As the diagnosis of food allergy is not certain with skin tests or blood tests, an oral food challenge is a more definitive test that allows the allergist to determine whether the individual is truly allergic to the food.
When children hesitate, or refuse to participate in oral food challenges, parents and clinicians may feel understandably frustrated. After all, the results of a food challenge can mean the difference between introducing a nourishing food into a child’s diet or having them continue to go without it.
We had the opportunity of interviewing allergist Dr. Julia Upton about her experiences with children who refuse, and her recommendations for moving past this issue. Dr. Upton is on staff at Toronto’s SickKids Hospital in the Immunology and Allergy Department. She is also an Assistant Professor in the Department of Paediatrics at the University of Toronto, and the Section Chair of Food Allergy and Anaphylaxis with the Canadian Society of Canadian Society of Allergy and Clinical Immunology (CSACI).
In your experience, how common is refusal of an oral food challenge by children? What does that typically look like?
We estimate that less than 2% of children booked for an oral food challenge refuse the challenge. However, these are children whose parents booked the challenge. There may be many more from the community office who are eligible for an oral food challenge who never agree to be booked.
In what age range is this most common?
In our experience, toddlers are the most likely to refuse. There are also the occasional older children who refuse.
Can you describe some of the reasons (if any) for the child’s refusal (e.g., is it due to fear, a history of anxiety or trauma due to anaphylaxis, or other factors)?
Some have said they are scared, either because they remember a reaction, or just because they have been told for so long that they must avoid the food, so it is hard to bring themselves to eat it. Some find the taste unappealing. There may be other reasons and factors.
How do you, your staff, and parents proceed when this occurs?
Refusing the food at the beginning is different than refusing the subsequent portions. For refusal at the beginning, we encourage the child to eat the food. Parents play a key role in knowing what their child likes, and to which rewards they will respond.
When the refusals begin during the challenge, we need to consider if the refusal is because of an allergic reaction. We ask about symptoms and perform a careful physical exam looking for hives, breathing changes, or circulation changes. If the child is well, we continue to encourage the child to eat the food. We also let them know that we haven’t seen any signs of an allergy.
Have you found any particular interventions (e.g., soothing, rescheduling) or tactics to be effective in helping the children agree to complete the challenge?
Providing information in advance of the appointment is helpful for the family, so that they know what to expect.
Children are all different, and some respond to rational discussion, such as explaining to older kids that it is their decision to eat the food or not, and we hope they do so we can learn the truth about their allergies. We might also explain that we need to do this to see if they still need to carry the epinephrine auto-injector.
Others may respond to treats and praise, while others respond to fantasy, such as being an allergy superhero and trying peanut to see if they have outgrown their allergy.
We find that giving some control to the child helps them feel like they are a part of the process.
We also try to reassure the family that we are ready to treat allergic reactions if they occur, and that an observed medical setting is a great place to find out the truth about their allergies.
Is there any advice you would provide to parents/guardians to help prepare their children for a food challenge prior to the appointment?
Parents often bring food in a form their child enjoys. For example, they may bring jam if the challenge food is in the form of a muffin (e.g., if they are challenging an allergen like egg that can be baked into the muffin). Or they may bring treats to eat, or video games as a reward. We find some parents have made a fun plan for the child to enjoy after the food challenge.
Bringing multiple forms of the food can help. For example, for a milk challenge, parents can bring regular milk and chocolate milk (if chocolate is appropriate for the child).
Another idea is bringing an appealing form of the food. For example, a parent may be able to bring French toast for egg rather than scrambled egg.
It is important to make sure the form of the food is right for the challenge and that the child can consume enough protein to get the true answer about their allergy.
If a child absolutely refuses to participate despite attempts to reassure them, how do you (and the parents) proceed in helping to evaluate and manage the child’s food allergy? What kind of treatment plan do you find most helpful?
If a child is thought to be allergic and did not complete a food challenge, then they continue to be considered allergic with the same management plan that was previously in place. If the child ate most of the food without an allergic reaction in our medically supervised setting and the child is at very low risk for anaphylaxis, then we may consider having the parents continue the challenge at home if they are comfortable doing so.
It is important for the family to know that we cannot remove the label of “allergy” unless we know that the child can eat a serving of the food without an allergic reaction. Sometimes this may require being re-booked at another time when they are ready for the food challenge.
Can you provide any further insight on this topic?
I would like to add a bit more context around oral food challenges please.
In our allergy clinic setting, we offer children oral food challenges if we think there is a reasonable chance that they may not be allergic to the food. Food challenges are required because testing for food allergy with skin and blood tests is not perfect. Skin and blood testing reveals only the statistical chance of whether or not a child will react to a food.
We book the food challenges for a time when the child is well, and we reschedule challenges if the child is unwell (e.g. if s/he is experiencing cold or asthma symptoms). Families are told in advance how the day will look and what form of the food is acceptable. We also explain that we will have the child eat the food until they demonstrate they can tolerate a serving with no allergic reaction, or until the first objective signs (symptoms that the medical team can see or measure) of an allergic reaction. It is always the child’s and family’s decision whether to continue a challenge. We do not force-feed the food. If there are objective symptoms, then the challenge is stopped for medical reasons, and appropriate treatment is provided. If there are only subjective symptoms (symptoms that only the child can feel), the challenge can be stopped, although it will not be considered diagnostic.
In research studies, a child undergoes a food challenge to confirm reactivity to the food.
Thank you, Dr. Upton!
For more information about oral food challenges, visit our web page on diagnosing food allergy.