A food challenge test is the best way to both confirm a food allergy and see if your child has outgrown a food allergy. Your child will be given small but increasing amounts of the food and monitored very closely for any reaction.
Only one food can be tested at a time. During the challenge test, your child will be in a hospital setting. By the end of the day, your child will need to ingest a serving size of the food in question.
If your child has an allergic reaction during the food challenge test:
- They will be treated by a team of physicians and nurses experienced in the management of allergic reactions.
- Medications such as epinephrine, antihistamines, steroids and albuterol will be given as needed. Occasionally, a child may need an IV line placed for administration of fluids and/or IV medications.
- To see if your child is allergic to a food to which she had a positive allergy test but has never before ingested
- To see if your child is allergic to a food when the allergy testing and history don’t correlate
- To see if your child has outgrown a food allergy
Your child ideally should have at least a 50 percent chance of passing the challenge. This is the case for almost all children who have only had a positive skin test but no clinical history of having reacted to the food in the past. For other children, the risk is estimated based on allergy testing, previous severity of reaction, and the passage of time. You may want to discuss your child’s specific risk with your allergist prior to the food challenge appointment.
Your child does not have to do a food challenge test. Remember, this is a decision made between your allergy team, yourself (or your family) and your child. Some families may prefer to wait until there is a greater chance of passing the challenge or the child is older.
It’s also important that you feel confident your child will eat the food. If your child is a very picky eater, has oral feeding issues, is anxious or is not ready for a challenge, it’s OK to postpone the challenge to a later time.
Be sure that you understand why a food challenge is being recommended. If you are unsure, don’t hesitate to ask questions before the challenge date.
Please call and cancel or reschedule the challenge. Allergic reactions can be more serious in a child who is already sick. We cannot perform a food challenge on a child if he is sick, recovering from a recent asthma flare (asthma symptoms within 1-2 weeks), or has a severe eczema flare/rash.
If your child arrives and is sick, a challenge will not be performed. You should not bring your sick child to food challenges for examination; instead, we may be able to help schedule an office visit if necessary.
Your child should stop taking all antihistamines prior to the challenge. Stop these medicines five days before the challenge:
- Allegra (fexofenadine)
- Zyrtec (cetirizine)
- Xyzal (levocetirizine)
- Benadryl (diphenhydramine)
- Atarax (hydroxyzine)
- Periactin (cyproheptadine)
Stop taking Claritin (loratadine) seven days before the food challenge.
Keep in mind that many over-the-counter cough and cold medicines also contain antihistamines. Please read the labels on any medication your child may take prior to the food challenge and do not take anything with antihistamines for at least three days before the challenge.
Your child should continue to take maintenance asthma medications (like Flovent, Advair and Singulair). Do not give Albuterol, Xopenex or other rescue inhalers on the morning of the challenge. If your child needs them, please call to cancel the appointment.
If your child is on other medications for other conditions, please let us know.
Your child may not have anything to eat after midnight the night before the test. (That means no breakfast the morning of your appointment.) During this time, you may give your child clear liquids only. Clear liquids include:
- Apple juice
- Fruit juices with no pulp
- Iced tea
- Water ice without fruit chunks
If your child is still breastfeeding, they may continue prior to the food challenge.
Due to limited space, we request that only 1-2 adults accompany your child. You should also expect that your visit may last through lunch.
You should bring:
- Challenge food: A nurse will contact you before the challenge to discuss exactly what type of food to bring for the challenge and how it should be prepared. We kindly ask that you also bring in the packaging in which the food came. It is very important to not bring foods that contain your child’s other allergens, as these will not be allowed. If given instructions on how to prepare food for the challenge (such as with baked egg/milk challenges), it is very important to follow instructions exactly. If there are any questions, please call our office during business hours before to your scheduled challenge.
- Toys and distractions: You and your child will be here for several hours. Favorite toys, DVDs, books, electronics, etc., will help to stay occupied.
- About 32 oz. of clear liquids for your child to drink during the challenge.
- Lunch for you and your child: She may be permitted to eat lunch/snacks approximately one hour after the last dose of challenge food is given.
- Change of clothing: For you and your child in case of vomiting.
Following the challenge
- Your child will have an allergic reaction. They will need to continue to avoid the food.
- Your child will tolerate the food. They will hold off on ingesting more of that food on the day of the challenge, but will then be instructed to keep the food in his diet.
- Your child refuses to eat a sufficient amount of the food, making the challenge results inconclusive.
Once at home, there is a rare chance that your child will have a delayed allergic reaction to the food challenge. Contact your allergist or the allergist on call immediately if this happens.
Rarely, a food allergy may recur after a child has passed a food challenge. We therefore recommend that your child keep the specific food in his diet about three times per week. Recurrence of allergy has infrequently been reported, and these episodes were associated with infrequent ingestion or avoidance of peanut.