What is a food challenge?
During a food challenge you will be given gradually increasing amounts of a specific food in a controlled and safe manner under close observation. The purpose of the challenge is to identify if you are allergic to that particular food and how much of that food it may take to cause a reaction. Sometimes it is necessary to “blind” the challenge, meaning the food to which you are being challenged is hidden in another food. This will be discussed and agreed upon in advance.
How to prepare for the food challenge?
Please follow these directions when getting ready for this test.
- Your doctor will ask you to bring in specific food for the food challenge (Baked Milk Recipe, Baked Egg recipe). You may also be asked to bring a favorite food in which to place/conceal the food to be challenged.
- Usually you eat only the food being provided during the food challenge. Please discuss this with your nurse and do not eat other foods during the food challenge.
- We do not want to perform the challenge if you are sick. This includes cold symptoms, diarrhea or a stomach ache, a body rash or atopic dermatitis flare. The food challenge results may be hard to interpret if these are present. If you have any questions, please call the allergy clinic in advance. The number to call is: (920) 969-1768
- Please make sure to have a family member or friend available to take you home in the event that you are given a medication during the challenge which could impair your ability to drive home.
- Please arrive 15 to 20 minutes before your challenge and check in at the Front Desk as soon as you arrive.
The following medicines might affect the results of the food challenge and will need to be stopped before the testing is done unless your doctor tells you otherwise.
If the medicine is not stopped before the food challenge we may not be able to perform the challenge.
All antihistamines will affect the results of some of these tests and need to be stopped before the testing is done. If you have any concerns about stopping antihistamines please check with your doctor before you stop the medicine.
Stop these antihistamines for the length of time listed before your appointment for the challenge:
Stop these oral antihistamines for 5 days before your appointment:
- Claritin® (loratadine)
- Allegra® (fexofenadine)
- Clarinex® (desloratadine)
- Zyrtec® (cetirizine)
- Xyzal® (levoceterizine)
Stop these oral antihistmanines for 3 days before your appointment:
- Actifed®, Dimetapp® (brompheniramine)
- Atarax®, Vistaril® (hydroxyzine)
- Benadryl® (diphenhydramine)
- Chlortrimeton® (chlorpheniramine)
- Phenergan® (promethazine)
- Tavist®, Antihist® (clemastine)
- Astelin®, Astepro®, Dymista® (nasal sprays)
- Actifed®, Aller-Chlor®, Bromfed®, Drixoral®, Dura-tab®, Novafed-A®, ine-D®, Trinalin® (Combination medicines)
If you are taking an antihistamine that is not listed, ask your doctor.
Some antidepressants can also act as an antihistamine. Let your doctor know if you are on any antidepressants before the food challenge. Do not stop the antidepressant without discussing it with your doctor.
Stop these medicines the night before your appointment:
- Singulair® (montelukast)
- Accolate® (zafirlukast)
Stop these medicines the morning of your appointment:
- Zyflo® (zileuton)
- Tagamet® (cimetadine)
- Zantac® (ranitidine)
- Pepcid® (famotidine)
- Axid® (nizatidine)
Continue to take all other medicines as you usually do.
What is done during the test?
You will check in to the Allergy and Asthma Center. Feel free to bring reading materials, a laptop or tablet to use during your food challenge.
You will begin the food challenge by eating a small amount of the suspected food. If the first dose is tolerated you will be given gradually increasing amounts of the food every 15 to 30 minutes until a normal meal-sized portion is eaten or the challenge is stopped because of symptoms or a reaction. You will be monitored closely during the food challenge by the nursing staff. Dr. Mjaanes will be available to provide evaluation or treatment in case of any symptoms.
Once the food challenge is done Dr. Mjaanes will discuss the results with you, answer your questions, and make recommendations.
How long will the food challenge take?
A single food challenge can take anywhere from 3-5 hours, but can take longer if you have a reaction. You should plan to spend at least half the day in clinic.