This topic is pretty fresh in my mind as my daughter underwent an oral food challenge to macadamia nuts last week. In case you’re not familiar with an oral food challenge (OFC), or haven’t experienced one yet, let us fill you in.
Today, oral food challenges are considered the gold standard for food allergy diagnosis in children and adults alike. Skin prick and blood tests aid in diagnosis, but they are prone to error—false positives are not uncommon. You can read more about food allergy diagnosis methods in our blog Food Allergies Today: An Expert Q & A.
There are typically three reasons why you might do an oral food challenge:
1. You or your child tested positively for a food allergy but have never actually eaten the food.
2. You or your child tested positively for a food allergy and have eaten the food before with no symptoms.
3. To see if you or your child has outgrown a known food allergy.
An oral food challenge is usually held at your allergist’s office over a few-hour period. The allergist administers tiny amounts of the potential allergen in gradually increasing doses over a set period of time (usually 3-6 hours). In my experience, the whole challenge start to finish lasts around 4 hours. Once the full serving is administered, the doctor will typically observe the patient for a couple hours to monitor for signs or symptoms of an allergic reaction. If symptoms occur at any point during an OFC, the challenge stops and symptoms are treated immediately.
Importantly, not everyone is a good candidate for an OFC. According to allergist Dr. Jordan Scott, “when asthma is flaring or when patients are ill, we don’t challenge.”
Let’s talk about what to expect. First, block off the day, because even if the OFC is expected to last only a few hours, the experience can be emotionally draining and stressful. Being prepared and understanding the purpose and procedure is incredibly important! Below you’ll find a list of things to prepare ahead of time so you can tackle the challenge head on.
Ask your allergist what he/she needs you to bring. He may ask you to provide the food for the challenge, or his office may provide the food (we’ve done both). If you’re providing the food, make sure you’ve done your homework to ensure it’s not processed in a shared facility or processed on a shared line with something else you’re allergic to. For example, when we challenged sesame a couple years ago, we ensured the hummus we brought wasn’t processed in a shared facility with nuts: my daughter’s other allergen. We didn’t want cross-contact playing a factor.
Ask your allergist what you should stop doing. Ask your allergist what medicines you need to stop taking before the challenge. Our allergist requires that we stop giving our daughter her daily antihistamines for seasonal allergies a few days before the challenge, as that could mask reaction symptoms during the OFC. Additionally, she cannot take any asthma medicine that day. However, if asthma symptoms start flaring, there’s a chance they’ll want to play it safe and reschedule your challenge anyway—clear communication with your allergist is key!
Bring lots of activities for entertainment. If the trial is for a child, I’ve found that new activities, games, and library books always help to hold their attention longer. Having a favorite stuffed “friend” or something that the child associates with comfort is helpful too. If you’re an adult, a good book and your favorite digital gadgets will probably suffice!
Pack safe snacks. If the challenge goes well, you may be at the allergist’s office for several hours. However, the tiny doses of food your allergist administers aren’t likely to fill you up ☺. We like to bring some of our daughter’s favorite tried and true snacks that we know are safe (another way to avoid bringing cross-contact into the equation!). Since the challenge is at an allergist’s office, and there will likely be patients in the near vicinity with food allergies, it’s an added bonus if you can bring foods that are free from the most common allergens: peanuts, tree nuts, fish, shellfish, wheat, egg, milk, and soy. I also bring disinfectant wipes in case the food spills so that I can clean it up properly for the next allergic patient. Good food allergy etiquette is important!
Bring your emergency medications. While this may seem unnecessary (hello, you’re at the allergist’s office ☺), it’s important. There’s always a small chance of a delayed reaction, and if that happens on the way home, you’ll want to have your epinephrine and antihistamines at the ready.
Stay calm. If you’re a parent accompanying a child to an OFC, it helps to remain calm if your child experiences an allergic reaction. “If a reaction occurs, it is important for parents to remain calm because children can pick up on the anxiety and feed on that,” allergist Dr. John Lee advises. If your child experiences a reaction, Dr. Lee also suggests that parents avoid calling it a “failed challenge” in front of their child, noting that “this can make a child feel as if they’ve somehow failed, or done something wrong.”
Leave the siblings at home. If the food challenge is for your child, it’s smart to leave any siblings at home so you can stay focused—especially in the event of an allergic reaction. Best-case scenario, your child doesn’t have a reaction and it ends up being quality time with your babe. If you’re an adult, you’ll still want to bring someone with you for support and to make sure you get home safely.
Set a course of action/next steps. Once the challenge is complete, talk to your allergist about next steps. If the challenge went well, make sure you know how to proceed with exposure to the food moving forward. If it didn’t, they may recommend future testing/follow up, and possibly strict avoidance of the food.
I hope you find these tips helpful! After experiencing my daughter’s first oral food challenge, I felt far better equipped to take on the second. In case you’re wondering, she passed her OFC to macadamia nuts! This is one nutritious food we can add back into her diet. Hooray!
If you’re interested in discussing oral food challenges further, let me know. We’ve been through several, so I know the ropes pretty well!
- Meg and the Allergy Amulet Team