Physicians encouraged to conduct oral food challenges for infants, toddlers

Key takeaways:

• Communication can help families prepare for a successful challenge.
• Physicians can be flexible in dosing amounts and schedules.
• Anaphylaxis during challenges can be educational opportunities for families.

BOSTON — Physicians should not hesitate to conduct oral food challenges for infants and toddlers, according to a presentation at the American College of Allergy, Asthma & Immunology Annual Scientific Meeting.

“Don’t be afraid of infant and toddler challenges, and don’t underuse them,” Aikaterini (Katherine) Anagnostou, MD, MSc, PhD, FACAAI, professor of pediatric allergy at Texas Children’s Hospital and Baylor College of Medicine, said during her presentation.

Anagnostou, who also is a member of the Healio Allergy/Asthma Peer Perspective Board, attributed the growing number of and need for these challenges in infants and toddlers to multiple factors.

“We have new prevention guidelines,” she said. “We know we can safely introduce foods to all infants.”

When parents introduce new foods to their infants and toddlers and are unsure if the child has had a reaction, they may need to bring the child to the clinic for an OFC, she explained.

Also, infants and toddlers are now getting more food allergy treatments such as oral immunotherapy and omalizumab (Xolair; Genentech/Novartis), and OFCs are part of their baseline and outcome assessments.

“So, we end up challenging this age more frequently,” Anagnostou said.

The most common reason for an OFC is the need to confirm or rule out a food allergy diagnosis, followed by the need to evaluate the patient’s threshold for allergic reactions before beginning treatment.

Anagnostou acknowledged that there is a lot of fear about OFCs in these age groups.

“From the toddler challenges, I want to reassure everyone, I think this age group is actually the easiest one to challenge,” she said.

Setting expectations

Before the OFC, Anagnostou advised clinicians and families to discuss whether testing is even the right option for the child.

“If, for example, they are never planning to incorporate the food into the diet, if they’re planning to avoid it anyway, and they don’t really care about it, then you may think a little bit differently about doing a very long and time-consuming procedure,” she said.

Clinics need to prepare the family with realistic expectations, Anagnostou said, since families often do not understand why they are getting the test, what they are supposed to do and what they are supposed to bring.

“This doesn’t necessarily have to be the physician’s job, although I try to tell them a few of these things when I see them in the clinic and I refer them to a food challenge,” she said.

“But there has to be somebody who actually communicates with these families and gives them the necessary information,” she continued. “If they don’t have it, I can guarantee that something is going to go wrong.”

Conversations about preparation can happen via telephone or video conference. Written information should be provided as well. Families should know what their child is going to eat, along with the size of the doses and how long the test will take.

Also, families should know that they need to bring the challenge food with them in a form that the child would eat, as well as additional food that the child has eaten before without any allergic reaction. The clinic additionally should discuss whether the child needs to stop taking any medications that they may be using before the OFC.

“These are all things that need to be covered with the family, and engaging with them is really quite important,” Anagnostou said.

Testing protocols

Next, clinicians need to determine age-appropriate portions to use during the test.

“We want to give them enough so that we can get an answer on whether they can actually go home and consume the food,” Anagnostou said. “But we don’t want to give them so much that they won’t be able to finish, or they may start gagging or vomiting, and then we aren’t sure how to interpret that.”

The goal is the top dose of the age-appropriate portion, which many guidelines define, Anagnostou said. But clinicians also should consult with parents on how much food that may be.

“Not everyone is the same, so there will be some infants and toddlers who can eat like there’s no tomorrow, and there’s going to be some infants and toddlers who are more picky, or they want to eat smaller portions, and that’s okay. We can be flexible,” she said.

The taste and texture of doses are important as well, Anagnostou said.

“It’s okay to use masking ingredients to change the taste to something that they may be more familiar with or acceptable of, because at the end of the day, what we want to do is we want to get them to eat the food, and we want to have an answer,” she said.

Masking ingredients may include milkshakes, yogurt, fruit purees, chocolate, ketchup, jam and jarred baby food, Anagnostou suggested.

Multiple guidelines provide dosing schedules, which Anagnostou called less complicated and more flexible than expected, adding that physicians can be creative.

“For those that you consider high risk, you will probably start at the lower doses and use lower doses,” she said. “For those that you consider low risk, you will start from higher doses, and you can use a smaller number of doses.”

The standard interval between doses is 15 to 20 minutes, Anagnostou continued, but physicians can extend that to 30 minutes or longer as needed if, for example, the child appears to be developing a reaction.

“We try to adhere to the schedule as best as possible, but on occasion, you might extend it if you need to,” she said.

Safety is another concern.

“There’s a lot of fear in this age group, although I think, again, they are probably the easiest and the safest to do,” Anagnostou said.

The most important step is ensuring that the child is well enough and does not have any concurrent illness on the day of the OFC to receive it, she continued.

Anagnostou also noted that criteria for differentiating between mild, moderate and severe reactions are available for determining when doses should be limited or if the OFC should be stopped, although physician assessments may vary.

“When I teach my fellows and when I talk to others, sometimes we actually may disagree on what we consider a mild reaction,” she said.

Anaphylaxis during OFCs

Anaphylaxis can be more challenging, Anagnostou continued, since infants are nonverbal and cannot tell physicians and caregivers what is happening.

“They’re not going to report any subjective symptoms to us,” she said.

Symptoms also may be difficult to interpret because they may be common in healthy infants, they might not be related to the OFC, or they might be nonspecific, although guidelines for recognizing anaphylaxis in infants are available as well, Anagnostou said.

When anaphylaxis does occur, it usually is not severe. Anagnostou cited one study that found a 0.81 per year rate of anaphylactic reactions among 512 infants aged 3 to 15 months with egg or milk allergy, with 70% that were mild, 18% that were moderate and 11.4% that were severe.

“There were still some severe reactions,” she said. “You can’t avoid it. They’re not going to be zero. But they are at a percentage that I think we can all handle, both emotionally and practically.”

Fatalities are rare, Anagnostou added. But comorbidities such as croup, bronchiolitis, asthma, and cutaneous mastocytosis with extensive skin involvement may increase the risk for severe anaphylaxis.

“It is important to remember not to challenge them when they are unwell,” Anagnostou cautioned.

Anagnostou cited another study of the most common severe food-induced allergic reactions in 193 infants and 181 toddlers, which included skin reactions (90%), facial and extremity swelling (59%), gastrointestinal issues (51%) and coughing/wheezing (45%).

The most common reactions in infants included skin reactions and skin mottling.

“This is good. We can see skin symptoms. We can assess those easily,” Anagnostou said.

Infants also more frequently pulled or scratched their ears or put their fingers in them.

“They couldn’t really verbalize their itching in those areas, but they could show it to us,” Anagnostou said.

Toddlers experienced throat itching and coughing/wheezing more often than the infants.

When anaphylaxis occurs, the child should receive epinephrine, which Anagnostou called a useful learning opportunity for parents despite the stress.

“You can take the parents aside and talk through with them about the symptoms and why they’re treating it with epinephrine and how it fits with the food allergy action plan,” Anagnostou said. “If possible, allow them to give the epi to the child. This can be a very valuable lesson, and it takes away the fear of using epinephrine.”

Other advice, conclusions

When children are being fussy, Anagnostou encouraged physicians to “just go with the flow,” do whatever it takes to complete the OFC, and maybe call on play leaders to make the test fun for the child.

“If the child is miserable, the parents are going to be miserable, and it’s going to be a very, very long day for everybody,” she said.

Anagnostou also said that families often ask her if their quality of life will improve after the test. She noted research that found improvements in quality of life regardless of whether the OFC was positive or negative.

“We can all think of various things that parents learned during the process of the food challenge, so that even when the child has a reaction, this can actually be a beneficial educational experience and hopefully take away some of the fear,” she said.

Families have asked her if the OFC will boost their child’s food-specific IgE and make the allergy worse. Anagnostou said other research has found no change in IgE or in skin prick test sizes after testing.

“Food challenges should not be deferred because of concerns that the reaction can cause sensitization,” she said.

With preparation and these protocols in place, Anagnostou said, physicians should be confident in conducting OFCs among infants and toddlers.

“If you have the infrastructure and resources to do food challenges, please do them,” she said. “They are one of the best diagnostic tools that we have as allergists.”

For more information:

Aikaterini (Katherine) Anagnostou, MD, MSc, PhD, FACAAI, can be reached at aikaterini.anagnostou@bcm.edu.